Medical interfaces and other medical devices, systems, and methods for performing eye exams

ABSTRACT

A mask for performing an eye exam of a subject includes one or more optically transparent sections for transmitting an incident light beam therethrough and incident on the subject&#39;s eye, in some embodiments, the one or more optically transparent sections are coated with an anti-reflective coating configured to reduce reflection of the incident light beam by the one or more optically transparent sections. In some embodiments, the one or more optically transparent sections may have a portion thereof that is tilted with respect to the incident light beam when the mask is optically interfaced with the docking portion of an ophthalmic instrument, such that the incident light beam forms a finite angle of incidence with respect to the corresponding portion of the optically transparent sections.

RELATED APPLICATIONS

This application is related to U.S. Provisional Application No.62/220,866, filed Sep. 18, 2015, U.S. Provisional Application No.62/220,194, filed Sep. 17, 2015, and U.S. patent application Ser. No.14/852,379, filed Sep. 11, 2015, which claims priority benefit under 37C.F.R. 119(e) to U.S. Provisional Patent Application No. 62/051,237,filed Sep. 16, 2014, U.S. Provisional Patent Application No. 62/050,034,filed Sep. 12, 2014, as well as U.S. Provisional Patent Application No.62/050,676, filed Sep. 15, 2014. Each of these above-referencedapplications is incorporated herein by reference in their entirety.

BACKGROUND Field

Embodiments of the present disclosure relate to the field of healthcare,including for example, devices, systems, methods of automating theprovision of diagnostic healthcare services to a patient as part of anexamination meant to detect disorders or diseases. In some but not allinstances, these healthcare services may apply only to eye careencounters, exams, services and eye diseases.

Description of the Related Art

Many people visiting medical offices often use the same equipment.Cross-contamination has become a problem of increasing concern,especially during certain periods such as flu season. As the provisionof healthcare becomes more automated, fewer office personnel may bepresent to clean devices between uses. Accordingly, systems and methodsfor improving hygiene are desirable.

SUMMARY

A wide range of embodiments are described herein. In some embodiments, amask may comprise a distal sheet member having one or more substantiallyoptically transparent sections and a proximal inflatable member having arear concaved surface that may face a first patient's face when in use.The rear concaved surface may be configured to conform to contours ofthe first patient's face. The inflatable member may have two cavitiestherein. The two cavities may be generally aligned with the one or moresubstantially optically transparent sections, and may extend from therear concaved surface toward the distal sheet member such that thecavities define two openings on the rear concave surface. The rearconcave surface may be configured to seal against the first patient'sface such that the first patient's eyes align with the two cavities, sothat the rear concave surface forms seals around a peripheral region ofthe first patient's eye sockets that inhibit flow of fluid into and outof the cavities. The mask may further comprise an ocular port providingaccess to at least one of the two ocular cavities for fluid flow intoand out of the at least one of the two ocular cavities and an inflationport providing access to inflate the inflatable member.

In various embodiments, the rear concaved surface may be configured toconform to the contours of the first patient's face with inflation ofthe inflatable member via the inflation port. The inflatable member maybe underinflated and the rear concaved surface may be configured toconform to the contours of the first patient's face with inflation ofthe underinflated inflatable member via the inflation port. The rearconcaved surface may be configured to conform to the contours of thefirst patient's face with application of negative pressure to theinflatable member via the inflation port. The mask may further compriseparticulate matter disposed within the inflatable member. Theparticulate matter may be configured to pack together with applicationof a negative pressure to the inflatable member via the inflation port,so that the rear concaved surface conforms to the contours of the firstpatient's face.

In various embodiments, the rear concaved surface may be configured toconform to contours of a second patient's face, wherein a contour of thesecond patient's face is different from a contour of the first patient'sface. The seals may be air-tight. The mask may further comprise a lipextending into at least one of the two cavities from a perimeter of atleast one of the two openings, the lip having distal ends curving towardthe distal sheet member in a default position, the distal endsconfigured to move rearwardly such that the lip seals against the user'sface upon introduction of positive pressure into the at least one of thetwo cavities. The inflatable member may be opaque.

In various embodiments, the distal sheet may be configured to interfacewith a medical device, which may be an eye exam device. The mask may beconfigured to couple with a docking portion on a medical device. Themask may be configured to couple with the docking portion via a flangethat slides into a slot of the docking portion. The inflation port andthe ocular port of the mask may be configured to couple with conduitends on a medical device. The ocular port and the inflation port mayinclude a male portion, wherein the conduit ends on the medical deviceinclude a female portion configured to slidably receive the maleportion. The ocular port and the inflation port may be configured tocouple with the conduit ends on the medical device substantiallysimultaneously.

Some embodiments relate to the utilization of devices that replace,augment, or enhance human laborers in a clinical health care setting.These devices may be used alone or in conjunction with other devicesused in exams such as exams of the eye.

For purposes of this summary, certain aspects, advantages, and novelfeatures of the invention are described herein. It is to be understoodthat not necessarily all such aspects, advantages, and features may beemployed and/or achieved in accordance with any particular embodiment ofthe invention. Thus, for example, those skilled in the art willrecognize that the invention may be embodied or carried out in a mannerthat achieves one advantage or group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, aspects and advantages of the presentinvention are described in detail below with reference to the drawingsof various embodiments, which are intended to illustrate and not tolimit the invention. The drawings comprise the following figures inwhich:

FIG. 1 schematically illustrates a perspective view of one embodiment ofa mask, which is inflatable and includes a framework that forms twocavities for the oculars.

FIGS. 2A-2B schematically illustrates a mask removably attached to amedical device.

FIG. 3 schematically illustrates a user wearing a mask that provides,for example, an interface to a medical device such as a diagnosticdevice that is used by many patients.

FIG. 4 schematically illustrates a perspective view of anotherembodiment of a mask with an inflatable framework that is partitionedinto two separately inflatable sections.

FIG. 5 schematically illustrates a cross section of the mask in FIG. 4taken along the lines 5-5.

FIG. 6 schematically illustrates a perspective view of anotherembodiment of a mask with a seal around the ocular cavities.

FIG. 7a schematically illustrates a side view of one embodiment of amask displaced a first distance from a medical device.

FIG. 7b schematically illustrates a side view of another embodiment of amask displaced a second distance from the medical device.

FIG. 8 schematically illustrates a schematic diagram of a system forcontrolling, monitoring, and providing fluid to a mask.

FIG. 9 schematically illustrates a schematic diagram an electronic examportal.

FIG. 10 schematically illustrates a healthcare office map.

FIG. 11 schematically illustrates a block diagram of a sample healthcareencounter.

FIG. 12 schematically illustrates a binocular eye examination systembased on optical coherence tomography.

FIG. 13 schematically illustrates a display of eye examination data.

FIGS. 14A-D schematically illustrate a mask having optically transparentsections that are tilted or sloped upward or downward and include ananti-reflection (AR) coating to reduce retro-reflection of light from anincident probe beam from an optical coherence tomography instrument backinto the instrument.

FIGS. 15A and 15B schematically illustrate the effect of a tilted orsloped window on a probe beam from the OCT instrument, which reducesretro-reflection into the optical coherence tomography instrument.

FIGS. 15C-E schematically illustrate the effect of a tilted or slopedwindow on a mask on the light reflected from an incident OCT probe beamand how tilting or sloping the window beyond the angle of the steepestray of light from the probe beam can reduce retro-reflection into theoptical coherence tomography instrument.

FIGS. 16A-D schematically illustrate a mask having optically transparentsections that are tilted or sloped nasally or temporally to reduceretro-reflection of light from an incident probe beam back into theoptical coherence tomography instrument.

FIGS. 17A-E schematically illustrate a curved window on a mask anddemonstrates how the location of the window with respect to the focus ofthe OCT instrument (e.g., oculars or eyepieces) can vary the amount ofretro-reflection of light from the optical coherence tomographyinstrument back into the OCT instrument.

FIGS. 18A-D schematically illustrate a mask having optically transparentsections that are curved to reduce retro-reflection of light from theoptical coherence tomography instrument back into the OCT instrument.

FIG. 19 schematically illustrate a curved window on a mask disposedforward of a pair of eyes separated by an interpupilary distance whereinthe window is increasing sloped more temporal from a center line throughthe window thereby exhibiting wrap that reduces retro-reflection oflight from the optical coherence tomography instrument back into the OCTinstrument.

FIGS. 20A-D schematically illustrate a mask having an optical windowhaving wrap as well as curvature in the superior-inferior meridian toreduce retro-reflection of light from the optical coherence tomographyinstrument back into the OCT instrument.

FIGS. 21A-27 and 29A-C schematically illustrate differently shaped maskwindows.

FIGS. 28A-D schematically illustrate design considerations indetermining the slope of the window at different distances from thecenterline through the mask.

FIG. 30A illustrates an embodiment of a receptacle for receiving a maskto be worn by a subject.

FIG. 30B illustrates receptacle mask attached to the contouredreceptacle of FIG. 30A.

FIG. 30C illustrates an embodiment of a contoured receptacle having aforehead shield and a nose shield.

FIG. 31 illustrates a mask attached to a contoured receptacle.

FIGS. 32A-32C illustrate a method of attaching a mask to the contouredreceptacle shown in FIG. 30A.

FIGS. 33A-33C illustrate a method of attaching a mask to anotherembodiment of the contoured receptacle.

FIGS. 34A-34C illustrate a method of attaching a mask to anotherembodiment of the contoured receptacle.

FIGS. 35A and 35B illustrate a method of attaching a mask to yet anothercontoured receptacle.

FIGS. 36A and 36B illustrate a user's head entering into a mask.

FIG. 37 illustrate a user's head in another embodiment of the mask.

FIG. 38 illustrates a contoured receptacle and mask constrainingmovement of a user's head.

FIGS. 39A-39D illustrate an embodiment of a mask.

FIGS. 40A-40D illustrate another embodiment of a mask.

FIGS. 41A-41D illustrate the mask shown in FIGS. 40A-40D attached to acontoured receptacle.

FIGS. 42A-42D illustrate the mask and contoured receptacle shown inFIGS. 41A-41D and a deformable portion.

FIGS. 43A-43C illustrate a method of inserting the mask assembly shownin FIGS. 42A-42D into an OCT device.

FIG. 44 is a flow chart of a method of using an interlock mechanism.

FIGS. 44A-44D schematically illustrate a method of using an interlockmechanism.

FIG. 45 illustrates another embodiment of the mask attached to thecontoured receptacle.

FIGS. 46A and 46B illustrate a mask assembly having a mask and adeformable portion.

FIGS. 47A and 47B illustrate a mask assembly having a mask, a contouredportion, and a deformable portion

FIG. 48A illustrates a posterior surface of an embodiment of a mask witha plurality of apertures for venting.

FIG. 48B illustrates an anterior surface of the mask shown in FIG. 48A.

FIG. 48C illustrates a cradle portion configured to interface with themask shown in FIGS. 48A and 48B.

FIG. 48D illustrates a posterior surface of another embodiment of a maskwith a plurality of apertures for venting.

FIG. 48E illustrates a posterior surface of yet another embodiment of amask with a plurality of apertures for venting.

FIG. 48F illustrates a posterior surface of yet another embodiment of amask with a plurality of apertures for venting.

FIG. 48G illustrates a posterior surface of yet another embodiment of amask with a plurality of apertures for venting.

FIG. 49 is a schematic representation of an embodiment of a cradleportion.

FIG. 50 is a schematic representation of another embodiment of a cradleportion.

FIG. 51 is a schematic representation of yet another embodiment of acradle portion.

FIG. 52 is a schematic illustration of a hygienic barrier.

DETAILED DESCRIPTION

Some embodiments disclosed herein provide an inflatable mask that caninterface with medical devices, such as medical diagnostic devices, suchas optical coherence tomography (“OCT”) devices. The inflatable mask canserve a variety of purposes, including maintaining a barrier between thepatient and the medical device to ensure cleanliness and hygiene,providing comfort to the patient, and stabilizing the patient's locationwith respect to the machine. In some embodiments, the inflatable maskcan form air-tight ocular cavities around the patient's eyes, allowingfor pressurization of the ocular cavities, in order to obtain ocularmeasurements. Additionally, various embodiments of an automatic portalsystem and an automated eye examination are disclosed herein.

Embodiments of the invention will now be described with reference to theaccompanying figures, wherein like numerals refer to like elementsthroughout. The terminology used in the description presented herein isnot intended to be interpreted in any limited or restrictive manner,simply because it is being utilized in conjunction with a detaileddescription of certain specific embodiments of the invention.Furthermore, embodiments of the invention may comprise several novelfeatures, no single one of which is solely responsible for its desirableattributes or which is essential to practicing the embodiments of theinventions herein described.

Inflatable Medical Interface

Referring to FIG. 1, in one embodiment, a mask 100 includes a distalsheet member (distal portion) 118 which has optically transparentsections 124, and a proximal inflatable member (proximal portion) 154having a generally concaved rear surface 122. In use, the rear concavedsurface 122 faces the patient's face and conforms to the patient's face,according to some embodiments. As used herein the terms “user” or“patient” or “subject” or “wearer” may be used interchangeably. StillReferring to FIG. 1, the inflatable member 154 can have two cavities 160a, 160 b which are aligned with the optically transparent sections 124.In some embodiments, the cavities 160 a, 160 b extend from a distalsheet 118 to the rear concave surface 122 and define two openings 162 onthe rear concave surface 122. In use, the patient's eyes align with thetwo cavities 160 a, 160 b, so that the rear concave surface 122 formsseals around the patient's eye sockets or face, e.g. forehead andcheeks, inhibiting flow of fluid into and out of the cavities 160 a, 160b. In addition, the mask 100 can include ports 170 a-b, 180 a-b whichprovide access to control flow of fluid (e.g. air) into and out of thecavities 160 a, 160 b.

In some embodiments, the mask 100 can interface with a medical device.With reference to FIGS. 2a-2b , there is illustrated one embodimentwhereby the mask 100 is placed on a separate device 112. In someembodiments, the separate device 112 is a medical device, such as adiagnostic or therapeutic device. In some embodiments, the separatedevice 112 is an ophthalmic device, such as a device for the eye, andmay be an optical coherence tomography device (“OCT”) that may contain ahousing and instrumentation contained therein. The mask 100 may be usedwith a wide range of medical devices 112, such as for example an OCTdevice such as disclosed herein, as well as other OCT devices and othermedical devices 112. In some embodiments, the medical device 112 canreceive and removably connect to the mask 100. The mask 100 can beconfigured to connect to the medical device 112, adhere to one or moresurfaces of the medical device 112, or be mechanically fixed to themedical device 112, or be secured to the medical device 112 in any otherway (e.g. clamps, straps, pins, screws, hinges, elastic bands, buttons,etc.), such that the mask 100 is removable from the medical device 112without damaging the mask 100.

In one embodiment, a docking portion 114, which may include an opticalinterface such as for example a plate, can be included on the medicaldevice 112. The docking portion 114 can also include a slot 116 forreceiving a mask 100. In some embodiments, the mask 100 includes aflange 164 that extends laterally outward past a side of the inflatablemember 154 on the distal sheet 118 for slidably engaging with the slot116. The mask 100 can be inserted into the slot 116 and slide down to afinal locking position 120. In another embodiment, the flange 164 can beon the medical device 112 and the slot 116 can be on the mask 100.

With reference to FIG. 3, there is illustrated an example of a mask 100worn by a user over the user's eyes. In various embodiments, the mask100 may be removably attached to the wearer with an adhesive, an elasticband, a Velcro band, a strap, a buckle, a clip, and/or any othersuitable fastener or mechanism. In some embodiments, the mask 100 caninclude mechanisms for both attaching to the wearer and attaching to themedical device 112. In other embodiments, a patient may use the mask 100without any straps, bands, etc. that attach to the user. For example,referring to FIGS. 2a-b , the patient may simply move his/her face inalignment and in contact with the mask 100, which is secured to themedical device 112. In another embodiment, a patient who has a mask 100secured to his/her face may position himself/herself properly withrespect to the medical device 112, so that the distal sheet 118interfaces with the medical device, 112, and the medical device 112 cantake readings.

Returning to FIG. 1, one embodiment of the mask 100 comprises aninflatable framework 154 having an inflatable chamber 154 a, twocavities 160 a, 160 b, a frontward surface formed by a distal sheetmember 118, and a rearward surface 122. It will be understood that“inflatable,” as used herein, can include “deflatable,” and vice versa.Thus, in some embodiments, an “inflatable” framework 154 or chamber 154a can be deflatable, and a “deflatable” framework 154 or chamber 154 acan be inflatable. Referring to FIG. 1, cavities 160 a, 160 b may extendbetween the distal sheet member 118 and the rearward surface 122. Insome embodiments, the frontward member 118 includes a window member 124,which can be substantially optically transparent in some embodiments,with minimal to no effects on the optics of a medical device 112 (e.g.an OCT device) which can interface with the mask 100, although someembodiments may introduce optical effects. In some embodiments, thedistal sheet member 118 can be rigid. In some embodiments, the distalsheet member 118 can be made of polycarbonate, poly(methylmethacrylate), or glass. Other materials can be used. In otherembodiments, the distal sheet member 118 can be flexible. The distalsheet member 118 can have a thickness of less than 0.1 mm, 0.1 mm, 0.5mm, 1 mm, 2 mm, 4 mm, or more. In one embodiment, the window member 124may be adjacent to the inflatable framework 154. Thus, the window member124 may form a frontward surface of a cavity 160 a, 160 b. Further, thewindow member 124 may be aligned with the cavities 160 a, 160 b. Inaddition, the cavities 160 a, 160 b can define openings on the rearwardsurface, defined by perimeters 162. Referring to FIG. 4, the inflatableframework 154 can have two separately inflatable chambers 150 a, 150 b.Still referring to FIG. 4, in one embodiment, one inflatable chamber 150a can have a cavity 160 a therein, and another inflatable chamber 150 bcan have another cavity 160 b therein.

The distal sheet member 118 may be substantially flat and the rearwardsurface 122 may be generally curved and concave according to oneembodiment. Referring to FIG. 4, in one embodiment the thickness of themask 100 is thinnest at the center 156 and thickest toward the outeredges 158, with the thickness decreasing from the outer edges 158 towardthe center 156, thereby defining a curved and concave rearward surface122.

During use, a patient's face is brought in contact with the rearwardsurface 122 of the mask, such that the patient's eyes are aligned withthe cavities 160 a, 160 b, and the patient “sees” into the cavities 160a, 160 b. Thus in some embodiments, the cavities 160 a, 160 b may bereferred to as ocular cavities 160 a, 160 b. In one embodiment, only theportion of the distal sheet member 118 that aligns with the patient'seyes may be optically transparent, with other portions opaque ornon-transparent.

In some embodiments, the rear concaved surface 122 of the mask 100 canseal against a patient's face around the general area surrounding thepatient's eyes sockets, thereby forming a seal around the patient's eyesockets. The seal may be air-tight and liquid-tight according to someembodiments. In some embodiments, a seal may be formed between the userand the mask 100 without the need for assistance from additionalpersonnel. In some embodiments, various portions of the patient's facecan form the seal around the ocular cavities 160 a, 160 b. For example,the patient's forehead, cheekbones, and/or nasal bridge (e.g. frontalbone, supraorbital foramen, zygomatic bone, maxilla, or nasal bone) canform a seal around the ocular cavities 160 a, 160 b. As used herein,reference to a “peripheral region” around the eye socket shall refer toany combination of the above.

FIG. 5 illustrates a top view of a patient wearing a mask 100. The mask100 in FIG. 5 is a cross-section of the mask 100 taken along line 5-5 inFIG. 4. Referring to FIG. 5, as seen from the view of the patient, themask 100 comprises a right cavity 160 b, such as a right ocular rightcavity, a left cavity 160 a, such as a left ocular cavity, a rightinflatable chamber 150 b, and a left inflatable chamber 150 b. The walls172 of the ocular cavities 160 a, 160 b, the window members 124, and thehead of the user 195 may form an air-tight enclosed area. The head ofthe user 195 (e.g. the peripheral region around the user's eye sockets)forms a seal with the rearward perimeters 162 of the cavities 160 a, 160b, thus allowing the cavities 160 a, 160 b to hold air or fluid. Thisseal may be capable of holding air or fluid pressures of, for example,0.5 psi, 1 psi, or 5 psi or pressures therebetween. Higher or lowerpressures are also possible.

Still referring to FIG. 5, some embodiments include inlet assemblies 155a, 155 b. The inlet assemblies may include ports 170 a-b, 180 a-b,allowing access to the inflatable chambers 150 a, 150 b, and/or thecavities 160 a, 160 b.

Air, fluid, and/or other substances can be introduced into the ocularcavities 160 a, 160 b, via ports 180 a, 180 b, 185 a, 185 b. Air may beintroduced into the left ocular cavity 160 a by supplying an air source(e.g. via a pump) to the port at 180 a. Thus, following the path of theair, the air may enter the port at 180 a, then exit the port at 185 aand into the left ocular cavity 160 a (180 a and 185 b represent twoends of the same path). Similarly, regarding the right ocular cavity 160b, air may enter the port at 180 b, and then exit the port at 185 b andinto the right ocular cavity 160 b.

Accordingly, in some embodiments, pressure inside the ocular cavities160 a, 160 b may be controlled by adjusting the amount of air into andout of the ports 180 a, 180 b. Further, the air tight seal formedbetween the patient's face and the mask 100 can prevent unwanted leaksinto or out of the ocular cavities 160 a, 160 b. This can beadvantageous when air or fluid is used to challenge or test a bodyfunction. For example, air pumped into sealed air chamber cavities 160a, 160 b in front of the eye can create positive pressure, which can beused to press on the eye for the purposes of measuring the force ofglobe retropulsion or measuring intraocular pressure. In addition, aircan be directed to the cornea, which is imaged with OCT. In someembodiments, air is pumped into the ocular cavities 160 a, 160 b toachieve a pressure of up to 1-2 psi. In some embodiments, the airsupplied to the ocular cavities 160 a, 160 b is supplied by ambientsurroundings, such as the ambient air in a clinical room using forexample a pump.

In some embodiments, chamber ports 170 a, 170 b, 175 a, 175 b provideaccess to inflatable chambers 150 a, 150 b for inflating or deflatingthe chambers 150 a, 150 b. The chambers 150 a, 150 b may be inflated byintroducing an air source (e.g. via a pump) to the ports at 170 a, 180a. Thus, for example, following the path of the air, the air may enterthe port at 170 a, then exit the port at 175 a and into the leftinflatable chamber 150 a, thereby inflating that chamber 150 a. Theright chamber 150 b may be inflated in a similar manner. Negativepressure (e.g. a vacuum) can be applied to the ports 170 a, 170 bconnected to the inflatable chambers 150 a, 150 b, thereby deflating thechambers 150 a, 150 b. As used herein, “deflating” shall includeapplying negative pressure.

In some embodiments, inflating the chambers 150 a, 150 b can cause themask 100 to conform to the contours of a user's face. In addition,deflating the chambers 150 a, 150 b can cause the mask 100 to conform tothe contours of a user's face. Further, inflating or deflating thechambers 150 a, 150 b can adjust a thickness of the mask 100, thuschanging the distance between a user (who may face the rear concavedsurface 122) and a medical device 112 (which may be interfaced with thedistal sheet member 118).

In various embodiments, a port 170 a-b, 180 a-b is provided for eachchamber 150 a, 150 b and cavity 160 a, 160 b. For example, referring toFIG. 5, there is illustrated a port 185 b for the right cavity, a port175 b for the right inflatable chamber 150 b, a port 185 a for the leftcavity 160 a, and a port 175 a for the left inflatable chamber 150 a.

In one embodiment, two ports may be provided for one inflatableframework 154. For example, returning to FIG. 1, one port 170 b isprovided on the right side of the inflatable framework 154, and anotherport 170 a is provided on the left side of the inflatable framework 154.Providing two ports for one chamber 154 can help to equalize thedistribution of substances (e.g. air or fluid) in the chamber 154 byallowing access to the chamber 154 at different regions. In oneembodiment, the inflatable framework 154 does not include any ports. Forexample, the inflatable framework 154 may be pre-formed as desired, byfilling it with a desired volume of fluid or air. Ports 170 a-b, 180 a-bmay be added, removed, arranged, or configured in any suitable manner.

In some embodiments, the mask 100 advantageously can conform to apatient's face, thereby allowing the formation of a complete air-tightseal between the peripheral region around a user's eye sockets and therear concaved surface 122 around the ocular cavities 160 a, 160 b.Accordingly, the rearward perimeter 162 of the cavities 160 a, 160 b canbe configured to sealingly engage a periphery of a patient's eye socket.In some embodiments, the mask 100 includes a recess 168 (see e.g. FIGS.1, 4, 6), allowing room for a patient's nose, so that the mask 100 formsa seal against the parts of a patient's face with a lower degree ofcurvature, increasing the surface area of the patient's face to whichthe mask 100 conforms.

In one embodiment, the air-tight seal can be formed by inflating theinflatable framework 154. In some embodiments, the inflatable framework154 can resemble a bag. In some embodiments, a mask 100 with arelatively deflated framework 154 is provided to a patient. Because thebag 154 is deflated, it may exhibit some “slack.” The patient's face maybe brought in contact with the mask 100, and then the bag 154 may beinflated, causing the bag 154 to inflate around the contours of thepatient's face and thereby conform to the patient's face. Accordingly, acomplete air-tight seal can be formed between the patient's face and therear concaved surface 122 around the ocular cavities 160 a, 160 b. Thebag 154 may be inflated by introducing air, gas, fluid, gel, or anyother suitable substance. In addition, the bag 154 can be deflated,causing the mask 100 to disengage from the patient's face, according toone embodiment.

In one embodiment, an air-tight seal is formed by applying a vacuum tothe inflatable framework 154. In some embodiments, when the framework154 is filled with particulate matter, such as coffee grounds, aplasmoid transformation to a semi-solid but form-fitting filler can beachieved by subjecting the particulate matter to a vacuum. For example,the framework 154 can be molded into shape easily when particulatematter is loosely contained in the framework 154, similar to a bean bag.A patient's face may then be brought into contact with the mask 100.Applying a vacuum to the bag 154 causes the particulate matter to packtightly, thereby causing the bag 154 to conform to the contours of apatient's face. The tightly packed particulate matter can thus undergo aplasmoid transformation to a solid, while still allowing the framework154 to conform to the patient's face and create an air-tight seal.

To facilitate the seal between a patient and the cavities 160 a, 160 b,the mask 100 can be configured with a lip 194 around the perimeter 162of a cavity 160 a, 160 b, as illustrated in FIG. 6. FIG. 6 illustrates alip 194 with a cut-away portion 161 showing the curvature of the lip194. In one embodiment, the lip 194 comprises a first end 196 attachedto the perimeter 162 of the cavity 160 a, 160 b and a second end 198extending partially into the cavity 160 a, 160 b. In one embodiment, theedge 198 of the lip 194 may extend more or less and curl inward, asillustrated in FIG. 6. In one embodiment, the first end 196 and secondend 198 define a curve, such that the lip 194 curls inwardly partiallyinto the cavity 160 a, 160 b. Further, the lip 194 can be flexible andconfigured to extend in a rearward direction (e.g. toward the rearwardsurface 122). Thus, when pressure is introduced inside the cavity 160 a,160 b, and pressure exerts a force in a rearward direction, the lip 194can move rearwardly. When the inflatable framework 154 is sealed with aperipheral region around a user's eye socket, and the lip 194 movesrearwardly, the lip 194 can seal against the user's eye socket,preventing pressure from escaping.

In some embodiments, the mask 100 can be configured to be comfortable byfilling the chambers 160 a, 160 b with soft gel fillers, particulatefillers such as foam beads or sand, or air fillers.

In one embodiment, the mask 100 can be custom made to fit the specificpatient using it. For example, the mask 100 may be molded for a specificpatient in a clinic. Thus, the mask 100 can be uniquely customized for aparticular patient according to one embodiment. In another embodiment,the mask 100 is a “one size fits all” mask 100. Other embodiments arepossible, including differential sizing based on age, height, or facialstructure. In some embodiments, the mask 100 is pre-inflated. Inaddition, air-tight seals can be formed between the rear curved surface122 of the mask around the ocular cavities 160 a, 160 b and theperipheral region around a patient's eye sockets (e.g. via a lip) whenthe mask 100 is pre-inflated.

FIGS. 7a-7b illustrate side views of a user with a mask 100 beingexamined or treated by a medical device 112 according to one embodiment.

It will be appreciated that the FIGS. 7a-7b are schematic drawings andmay possibly exaggerate the variation in size for illustrative purposes.The medical device 112 shown in FIGS. 7a-7b can be an OCT device.Inflating the mask 100 can increase the thickness of the mask 100, sothat the mask 100 can move the patient toward or away from the device112 when it is deflated or inflated respectively. For example, FIG. 7aillustrates a relatively deflated mask 100, with a user relatively closeto the device 112. FIG. 7b illustrates a relatively inflated mask 100,with the user relatively farther from the mask 100. “Inflating” or“inflated” may include a mask 100 in a fully inflated state, or a mask100 in a less than fully inflated state, but still in a state that ismore inflated relative to a previous state (e.g. a deflated state) or atleast partially inflated. Similarly, “deflating” or “deflated” mayinclude a mask 100 in a fully deflated state, or a mask 100 in a lessthan fully deflated state, but still in a state that is more deflatedrelative to a previous state (e.g. an inflated state) or at leastpartially deflated.

A patient location sensor 166 can be included in order to detect howclose or how far the user is from the medical device 112. If the user isnot at a desired distance from the device 112, the framework 154 on themask 100 can be inflated or deflated to bring the user to the desireddistance. Any variety of sensors 166 can be used to detect the distancebetween the user and the medical device 112, according to sensors knownin the art. In one embodiment, a patient location sensor 166 can beincluded with the medical device 112 in alignment with the user'sforehead, as illustrated in FIGS. 7a-7b . Thus, the location sensor 166can measure, for example, the distance or relative distance from theforehead to the medical device 112. In one embodiment, the sensor 166can be a switch, which can be actuated (e.g. activated or depressed)when the user's forehead presses against the switch when the user isclose to the medical device 112. In addition, other types of sensors indifferent locations could measure the distance between the user and themedical device 112. In one embodiment, the location sensor 166 is notplaced on the medical device 112, but is placed in a location that canstill detect the distance between the user and the medical device 112(e.g. on the walls of a room in which the medical device 112 islocated). In one embodiment, the information regarding the distancebetween the user and the medical device 112 is provided by an OCTdevice.

FIG. 8 illustrates a system 174 for controlling, monitoring, andproviding air to the inflatable mask 100. The system 174 can be used tocontrol a patient's distance from the medical device 112, the patient'smovement to and from the medical device 112, the seal between the mask100 and the patient's face, and/or pressure in the ocular cavities 160a, 160 b of the mask 100.

Referring to FIG. 8, the system 174 can include pumps 176, an air source176, conduits 178, valves 182, pressure sensors 188, flow sensors 188and/or processors (not shown). In addition, air into and out of theinflatable chambers 150 a, 150 b and/or cavities 160 a, 160 b can becontrolled by similar components. Referring to FIG. 7b , the airsource/pump 176, valves 182, sensors 188, and the mask 100 can be influid communication with each other via conduits 178. In addition, theair source/pump 176, valves 182, and sensors 188 can be in electroniccommunication with a processor. Further, the processor can be incommunication with electronics associated with a medical device 112,such as an OCT device.

In some embodiments, the air source/pump 176, conduits 178, valves 182,sensors 188, and processors can be contained within a single unit, suchas a medical device 112. In other embodiments, the components may bespread out across several devices external to a medical device 112.

Referring to FIG. 8, the mask 100 can be connected to an air source/pump176, which can comprise compressed air, ambient air from the environmentof the mask (e.g. in a clinical room), a reservoir, a sink (e.g. forproviding water to the mask 100), an automatic pump, manual pump, handpump, dispenser, or any other suitable air source/pump.

Valves 182 can also be included in the system 174 for increasing,decreasing, stopping, starting, changing the direction, or otherwiseaffecting the flow of air within the system 174. In some embodiments,the valves 182 can direct air to an exhaust port, in order to vent airin the cavities 160 a, 160 b or inflatable chambers 150 a, 150 b. Insome embodiments, valves 182 are not included in the ports 170 a-b, 180a-b of the mask 100, and are external to the mask 100. In someembodiments, valves 182 can be included in the ports 170 a-b, 180 a-b ofthe mask 100.

In some embodiments, the system can also include an ocular pressuresensor 186 to sense the pressure inside the ocular cavities 160 a, 160b. Readings from the pressure sensor 186 can be used for intraocularpressure and retropulsion measurements. In addition, the system 174 caninclude a chamber pressure sensor 184. In some embodiments, the chamberpressure sensor 184 can be used to determine whether a patient ispressing their face against the mask 100, or how hard the patient ispressing their face against the mask 100.

A flow sensor 188 can also be provided to measure the volume of flowinto and out of the ocular cavities 160 a, 160 b and inflatable chambers150 a, 150 b. Flow sensors 188 may be useful when, for example, theinflatable chamber 150 a, 150 b is underinflated such that the pressureinside the inflatable chamber equals atmospheric pressure. In such acase, pressure sensors 188 may not be useful but a flow sensor 188 canmeasure the volume of fluid pumped into the inflatable chamber 150 a,150 b. In some embodiments, one set of sensors can be provided for theocular cavities 160 a, 160 b, and another set of sensors can be providedfor the inflatable chambers 150 a, 150 b.

Referring to FIG. 8, the conduits 178 can convey the flow of air (orgas, liquid, gel, etc.) between the pump/air source 176, valves 182,sensors 188, and the mask 100. In some embodiments, the valves 182 canbe downstream of the pump/air source 176, the sensors 188 can bedownstream of the valves 182, and the mask 100 can be downstream of thesensors 188.

In some embodiments, the conduit 178 terminates at conduit ends 192,shown in FIGS. 2a-2b . The conduit ends 192 can be designed to couplewith the ports 170 a-b, 180 a-b of the mask 100. Referring to FIGS. 2a-b, in some embodiments, the ports 170 a-b, 180 a-b of the mask 100 caninclude a male portion (e.g. a luer lock taper connector), and theconduit ends 192 can include a female portion.

In some embodiments, the ports 170 a-b, 180 a-b of the mask 100 caninclude a female portion, and the conduit ends 192 can include a maleportion. In addition, the conduit ends 192 and the ports 170 a-b, 180a-b can contain flanges, tubings, or any other mechanism for couplingwith each other. When the ports 170 a-b, 180 a-b are coupled to theconduit ends 192, an air-tight seal for fluid flow between the mask 100and the system can be created.

Referring to FIG. 2a , in some embodiments, one movement (e.g. pressingthe mask 100 down in the direction of the arrow 199) can connect allfour ports 170 a-b, 180 a-b to the conduit ends 192 at the same time. Insome embodiments, the conduit ends 192 extend to the exterior of themedical device 112, and the conduits 178 can be connected to theexterior ports 170 a-b, 180 a-b one at a time. In some embodiments, theconduits ends 192 are located on the medical device 112, and a separateconduit piece can connect the conduit ends 192 to the external ports 170a-b, 180 a-b.

In some embodiments, the system 174 can be used in clinical settings,such as during a medical visit (e.g. a medical examination). Thecomponents can be utilized in a variety of different ways andcombinations during the medical treatment.

For example, during a medical diagnostic or treatment, referring to FIG.2a , the mask 100 can be interfaced with the medical device 112 byaligning the ports 170 a-b, 180 a-b of the mask 100 with the conduitends 192 in the medical device 112, and pushing down on the mask 100.

The patient's head can be brought into contact with the rear concavedsurface 122 of the mask 100, and system 174 can inflate or deflate theinflatable chambers 150 a, 150 b, so that the mask 100 conforms to thepatient's face, thereby forming an air-tight seal around the ocularcavities 160 a, 160 b.

During the procedure, the system 174 can change the pressure in theair-tight ocular cavities 160 a, 160 b by a desired amount depending onthe medical examination being taken. The pressure sensor 186 can sensethe amount of pressure in the ocular cavities 160 a, 160 b, and sendthat data to the processor. In addition, the system 174 can vary thepressure in the ocular cavities 160 a, 160 b during the procedure. Forexample, the processor can increase the pump 176 speed or change thevalve state 182 so that flow is restricted.

Other components in the medical device 112 can also take measurements,such as ocular measurements, which can be combined with the data sent bythe pressure sensors. For example, optical imaging components canmeasure changes in curvature or position of the anterior of the eye andin some embodiments, compare those changes to changes in the position orcurvature of posterior of the eye. In addition, changes in the locationsand distances of tissues, such as in the eye, can be imaged based on thepressure in cavities 160 a and 160 b sensed by the pressure sensors.Thus, various pieces of data can be analyzed and processed intomeaningful medical information.

Further, during the procedure, the system 174 may receive data from apatient location sensor 166 (see e.g. FIG. 7a-7b ) indicating thedistance between the patient and the medical device 112. The processormay determine that the patient should be positioned closer to or fartheraway from the medical device 112, in order to obtain more accurate andprecise readings. Thus, the processor may use the location of thepatient to modulate the inflation or deflation of the mask 100 more orless (e.g. by changing pump speed, changing valve state, etc.), in orderto bring the patient closer to or farther away from the medical device112.

In some embodiments, the processor can switch on the pump/air source 176and open the valves 182 to introduce air into the ocular cavities 160 a,160 b or inflatable chambers 150 a, 150 b according to a preset pressureor flow volume goal. In addition, flow in the system can be reversed todeflate the inflatable chambers 150 a, 150 b.

The mask 100 may include a mechanism for easily identifying a patientaccording to one embodiment. For example, the mask 100 may include anRFID tag, bar code or QR code, or other physical embodiment, to identifythe wearer to other devices. Thus, for example, when a patient with acertain mask 100 nears the medical device 112, the system can determinewho the patient is, and execute instructions tailored for the patient(e.g. how much air is needed to properly inflate the framework 154, howmuch pressure should be applied to the ocular cavities 160 a, 160 b,what readings the medical device 112 should take, etc.)

The mask 100 can be made of a material, such as plastic (e.g.polyethylene, PVC), rubber paper, or any other suitable material. Invarious embodiments, the mask 100 can be configured to be disposable bymaking it out of inexpensive materials such as paper, rubber, orplastic. In various embodiments, the mask 100 can be configured to bereusable and easily cleaned either by the wearer or by another person.

In some embodiments, the mask 100 can provide a barrier between thepatient and the medical device 112, increasing cleanliness and servinghygienic purposes.

In one embodiment, the mask 100 can be configured to create a barrier toexternal or ambient light, such as by constructing the mask 100 out ofopaque materials that block light transmission. Accordingly, the mask100 can prevent ambient light from interfering with medical examinationmeasurements, such as optical devices, and ensure the integrity of thosemeasurements.

Although examples are provided with reference to “air” (e.g. introducingair into the inflatable chamber, introducing air into the ocularcavities), it will be appreciated that other substances besides air canbe used, such as gas, fluids, gel, and particulate matter.

Although examples are provided with reference to a mask 100 for abinocular system, it will be appreciated that the embodiments disclosedherein can be adapted for a mono-ocular system. Thus, in one embodiment,the mask 100 includes an inflatable framework 154 defining one cavityinstead of two, and that cavity can form a seal against the periphery ofone eye socket. Further, while examples are provided with reference toeye sockets and eye examinations, it will be appreciated that theembodiments disclosed herein can be used with other tissues and medicalapplications.

In other embodiments, an inflatable device may cover different bodytissues such as gloves for the hands, stockings for the feet or a hatfor the head. In various embodiments, the inflatable device may includea cavity similar to the ocular cavity in the mask and may have at leastone port to provide access to the cavity and change pressure therein orinflow gas therein or outflow gas therefrom, as well as a port toinflate the inflatable devices.

The inflatable mask can be used in a wide variety of clinical settings,including medical examinations and encounters that may be assisted byautomated systems. Various embodiments of an automatic encounter portalare described below.

Electronic Encounter Portal

Medical encounters can be commonly comprised of administrative tasks,collection of examination data, analysis of exam data, and formation ofan assessment and plan by the healthcare provider. In this context, ahealthcare provider may be a licensed healthcare practitioner, such as amedical doctor or optometrist, allowed by law or regulation to providehealthcare services to patients. Examinations may be comprised ofnumerous individual tests or services that provide information for ahealthcare provider to use to make a diagnosis, recommend treatment, andplan follow-up. The data from these tests that are collected for use byhealthcare providers can be broken down into three rough categories:historical data, functional data, and physical data.

Historical data can be collected in many ways including as a verbalperson-to-person interview, a written questionnaire read and answered bythe patient, or a set of questions posed by an electronic device eitherverbally or visually. Typical categories of historical information thatare obtained in medical exams can include but are not limited to a chiefcomplaint, history of present illness, past medical history, past ocularhistory, medications, allergies, social history, occupational history,family history, sexual history and a review of systems.

Functional data can be collected through individual tests of functionand can be documented with numbers, symbols, or categorical labels.Examples of general medical functions can include but are not limited tomeasurements of blood pressure, pulse, respiratory rate, cognitiveability, gait, and coordination. Ophthalmic functions that may be testedduring an exam can include but are not limited to measurements ofvision, refractive error, intraocular pressure, pupillary reactions,visual fields, ocular motility and alignment, ocular sensation,distortion testing, reading speed, contrast sensitivity, stereoacuity,and foveal suppression.

Physical data can capture the physical states of body tissues and can becollected in many forms, including imaging, descriptions or drawings, orother physical measurements. This may be accomplished with simplemeasurement tools such as rulers and scales. It may also be accomplishedwith imaging devices, such as color photography, computed tomography,magnetic resonance imaging, and optical coherence tomography (OCT).Other means to measure physical states are possible. Physicalmeasurements in general medical exams can include height, weight, waistcircumference, hair color, and organ size. Ophthalmic structuralmeasurements can include but are not limited to slit lamp biomicroscopy,retinal OCT, exophthalmometry, biometry, and ultrasound.

Currently, almost all of the individual tests that make up a medicalexamination are conducted by a human laborer often through the operationof a device. Whether this person is a healthcare provider or an alliedhealthcare professional, these laborers can be expensive, can oftenproduce subjective results, and can have limitations on their workingcapacity and efficiency. Given the labor intensive nature of exams,healthcare care practices (which may also be referred to herein as“clinics” or “offices”) and in particular eye care practices oftenemploy numerous ancillary staff members for every healthcare providerand dedicate large areas of office space for waiting rooms, diagnosticequipment rooms and exam rooms. All combined, these overhead costs makehealthcare expensive, inefficient and often prone to errors.

Automation is a well-known way of improving efficiency and capacity aswell as reducing unit costs. Patient-operated or entirely operator-lessdevices may be preferable as labor costs increase and the need forobjective, reproducible, digital, quantitative data increases.

With reference to FIG. 9, there is illustrated one embodiment of anelectronic encounter portal. The encounter module 200 can be anelectronic device that may be comprised of, for example, data storage,communication, or computer code execution capabilities and may containinformation on patients registered for a healthcare encounter in anoffice.

The office interface 210 can be comprised of software that may be usedby people to interact with the encounter module 200. Other software mayalso be included in the office interface 210. In one embodiment, theoffice interface 210 also can be comprised of an electronic device, suchas a computer, tablet device, or smartphone. In various embodiments,office staff can use the office interface 210 to, for example, createrecords or enter patient data into the encounter module 200 for patientswho register in the clinic. This data entry can be enabled in many ways,including for example, manual entry, entry by copying previously-entereddata from an office database 220, or entry using a unique identifierthat can be compared to an office database 220 or external database 230,such as an Internet or cloud-based database, to retrieve pre-entereddata for a patient matching that unique identifier. In one embodiment,registration can be completed with a code, such as an encounter code, ina fashion similar to checking in for an airline flight at an airport.This code could, for example, be linked to patient or providerinformation required for registration purposes.

The office database 220 can be configured to store data from pastencounters, as well as other types of data. The external database 230can be also configured to store at least data from past encounters, aswell as other types of data. The encounter module 200 can be configured,for example, to access, copy, modify, delete, and add information, suchas patient data, to and from the office database 220 and externaldatabase 230. The external database 230 can be configured to, forexample, receive, store, retrieve, and modify encounter information fromother offices.

In one embodiment, patients may self-register or check into the clinicby using the office interface 210 to, for example, create an encounterrecord, enter encounter information manually, select their informationfrom a pre-populated office database 220, or enter a unique identifierthat can be compared to an office 220 or external database 230 toretrieve their other associated data.

The encounter module 200 can be configured to contain patient records,which may also contain clinic processes 205. A clinic process 205 can becomprised of, for example, orders from the healthcare provider for thepatient's care. In one embodiment, the orders may indicate the sequenceof evaluations and care. For example, a provider may indicate that agiven patient should undergo a medical history followed by anexamination with various medical devices followed by an assessment bythe provider.

In one embodiment, the clinic process 205 can be configured to enablealteration of the orders, the order sequence or both the orders andtheir sequence by, for example, office staff or the provider. Examplesof this could include insertion of an educational session about a givendisease prior to a discussion with the provider, deletion of a treatmentdenied by a patient, or switching the sequence of two test procedures.

In some embodiments, the prescribed orders themselves may contain listsof prescribed tests to be performed on a given device. For example, aspart of a technician work-up order, a provider may prescribe bloodpressure and pulse measurement testing to be performed on a patientusing a device in the clinic. The order and prescription of these testsmay change throughout the encounter having been altered by office staff,the provider, or electronic devices.

In one embodiment, a diagnosis or medical history of a patient from theencounter module 200 can be included in the clinic process 205 and maybe used, for example, to determine or alter the clinic process 205. Forexample, a history of past visits and evaluations may alter the teststhat are ordered or the devices that are used during an encounter.

In one embodiment of an electronic encounter portal, a tracking system240 can be configured to enable a component of an electronic encountersystem to determine the physical location or position of, for example,patients, providers and staff in the office space. In one embodiment, acomponent of the electronic encounter system can use data from thetracking system 240 to monitor the progress of patients through a clinicprocess 205. In one embodiment, this tracking system 240 can becomprised of a sensing technology, such as a compass, radiofrequencyantenna, acoustic sensor, imaging sensor, or GPS sensor that determinesthe position of the sensor in relation to known objects such as officewalls, positioning beacons, WiFi transmitters, GPS satellites, magneticfields, or personnel outfitted with radiofrequency ID tags.

The tracking system 240 may also be configured to perform mathematicalcalculations, such as triangulation, to analyze signals from thesensors. The tracking system may also compare signals from the sensorsto databases of known signals collected at a prior date, such ascomparing a measured magnetic field to a database of known magneticfields at every position in the clinic. In some embodiments, thistracking system 240 can also be comprised of an emission technology suchas a radiofrequency beacon, to indicate the position of an object in theoffice space.

The tracking system 240 may also be configured to localize the positionof a person or object using a known map of the office space as shown inFIG. 3. Knowledge of the position of sensors, patients, or personnel inan office space map may enable the tracking system 240 to provideinformation to the encounter module 200 regarding the location ofpatients, providers or other office personnel in an office space.

The tracking system 240 can also be configured to provide positioninformation to other components of the electronic encounter system, suchas the office interface 210 or the patient interface 250, eitherdirectly or via an intermediate component such as the encounter module200. An example of how this information might be used is to providestatus information to a user as to the progress or status of otherpeople in the office.

In one embodiment, office personnel can use the office interface 210 tomonitor the location or progress of, for example, providers, staff orpatients within the office space. This monitoring may includecalculation of, for example, time spent in a given location, progressthrough a clinic process 205, or current status of activity, such aswaiting, working or occupied. This monitoring ability can beadvantageous so that office staff can, for example, monitor delays inthe provision of patient care or identify recurrent patient flowbottlenecks that can be reduced through optimization of clinic flow.

The patient interface 250 can be comprised of software that may be usedby patients to interact with the encounter module 200. In oneembodiment, the patient interface 210 can also comprise an electronicdevice, such as a computer, tablet device, or smartphone, which can besupplied by the clinic or be supplied by the patient. For the purpose ofclarity, in one embodiment, the patient interface 250 may be thepatient's own electronic device, such as a smartphone or computer thatcan be configured with patient interface 250 software. In otherembodiments, the office interface 210 and the patient interface 250 maybe the same device, such as with a mobile tablet computer or smartphone,that can be configured to allow a patient to perform actions of both anoffice interface 210, such as registration, and actions of a patientinterface 250, such as viewing patient data or asking electronicquestions of office personnel.

The encounter module 200 and the patient interface 250 can be configuredto interface with various devices 260 in the clinic. These devices 260can include but are not limited to diagnostic instruments, such as bloodpressure monitors, imaging devices or other measurement instruments, ortherapeutic devices, such as lasers or injection apparatuses. Theencounter module and the patient interface 250 can be configured to sendand receive data with these devices 260. Communication with thesedevices 260 can be enabled by but is not limited to wired connections,wireless connections and printed methods, such as bar codes or QR codes.

With reference to FIG. 3, there is illustrated a map of a healthcareoffice. In one embodiment, the patient can register for a healthcareencounter at the office entrance 300. In other embodiments, the patientmay register for a healthcare encounter at a place other than entrance300. In one embodiment, encounter registration can be completed by ahuman receptionist who may enter information into the encounter module200 through the office interface 210. In another embodiment,registration may be completed by the patient for example by using anassisted or self-service kiosk configured with an office interface 210.

A kiosk may, for example, be comprised of a location where an untraineduser can perform a task or tasks, such as checking in for an appointmentor performing a requested test. This kiosk may be comprised ofelectronics or computer equipment, may be shielded from the view ofother people in the same room, may be comprised of seating, and mayprovide a material result to a user. Other kiosk configurations arepossible.

In another embodiment, the patient may register for the encounter withan office interface 210, such as a tablet computer, that is supplied bythe clinic and may have been configured with software to interface withthe encounter module 200. In still another embodiment, the user mayregister for the encounter with their own portable device, such as amobile phone or tablet computer, that can be configured with softwarethat can allow it to act as either or both an office interface 210 or asa patient interface 250.

In various embodiments, orders or steps in an electronic encountersystem can include, for example, asking a patient to sit in waiting area310, asking a patient to proceed to testing area 320 or asking a patientto go to clinic area 330. These orders can be conveyed to the patientby, for example, the patient interface 250 or by office personnel. Inone embodiment, the desired disposition for a patient can be determinedby a clinic process 205 that may have been entered into the encountermodule 200 and communicated to the patient via the patient interface 250or office personnel.

In one embodiment, the patient interface 250 can be configured to useinformation from the tracking system 240 for example, to determine thelocation of the patient in the clinic, to determine the next plannedlocation for a patient from a clinic process 205 in the encounter module200, or to communicate directions to a patient using the patientinterface 250.

Referring to FIG. 10, in one embodiment 340, a line can be drawn on aschematic map of the clinic space on patient interface 250 to show thepatient how to walk to their next destination in the clinic. In anotherembodiment, the patient interface 250 can be configured to communicatedirections verbally, such as by text-to-speech software.

In one embodiment, the encounter module 200 may be configured to monitorwhich rooms and devices in an office are “in use” based on informationprovided by the tracking system 240. In one embodiment, the encountermodule 200 may be configured to select a next location for a patientbased on which rooms or devices 260 may be free to use. For example, ifthe encounter module 200 determines that a device 260 required for thenext stage of a clinic process 205 is occupied or busy, the encountermodule 200 can be configured to alter the clinic process 205 byinserting, for example, a waiting room order that, for example, can beremoved from the clinic process 205 when the required device is free foruse.

In one embodiment, the encounter module 200 can be configured to monitorutilization of a device 260 or clinic area that may be required for thenext stage of a clinic process 205 and may be configured to insert anorder for a patient to move to that device 260 or clinic area when itbecomes free for use.

In another embodiment, the encounter module 200 can be configured tomonitor the list of patients waiting for a provider and also todetermine which providers have the shortest waiting lists or waitingtimes based on, for example, the number of patients in a waiting patientlist and the average time the provider spends with each patient. Theencounter module 200 can be configured to use this information, forexample, to assign patients to providers with the shortest wait times soas to improve clinic flow. Numerous other embodiments of devicedecisions based on dynamic knowledge of device and space utilizationwithin an office space are possible.

An example of a healthcare encounter is shown in FIG. 11. In oneembodiment, the first step in the encounter may be registration 400,which can be completed, for example, by office staff or by the patientusing, for example, an office interface 210. Encounter registration 400may be comprised of many steps such as signing the patient's name andaddress, presenting identification, verifying insurance status, payingco-payments due prior to the encounter, consenting to be seen by theprovider, consent to privacy regulations or payment of other fees. Inother embodiments, the user may skip registration 400 and may proceed toother steps, such as examination 410.

In one embodiment, one step in an automated healthcare encounter can beverification of the user's identity. This may be accomplished, forexample, as part of registration 400, as part of examination 410, priorto using any device 260, or at other times in the encounter. A mobilepatient interface 250 may be advantageous since it can verify the user'sidentity once and then communicate this identity to, for example, theencounter module 200, to providers, or to subsequent devices usedthroughout the encounter, such as devices 260.

In various embodiments, the patient interface 250 can be configured toverify the user's identity through biometrics, such as throughrecognition of the patient's face, voice, fingerprint or other uniquephysical aspects of the subject. In other embodiments, the patientinterface 250 can be configured to verify the user's identity throughconfirmation of a user's unique data, such as their names, date ofbirth, addresses, mother's maiden name, or answers to questions onlyknown to the user. In another embodiment, the patient interface 250 canbe configured to verify the user's identity through confirmation ofcode, such as a password or secret code known only to the user. In stillanother embodiment, the patient interface 250 can be configured toverify the user's identity through coupling of a device carried only bythe user, such as a key, electronic device, bar code, or QR code.

In one embodiment of an electronic healthcare encounter, the user maycomplete the history portion of their examination as part of theiroverall encounter. As discussed previously, in various embodiments, thehistory portion of the encounter can be collected, for example, byoffice staff or by the patient themselves. Office staff may use thepatient interface 250 or the office interface 210 to conduct or enterresults from a patient history. In other embodiments, the patient mayuse the patient interface 250 to complete their own history withoutinteracting with office staff.

In various embodiments, the questions can be configured in a form thatfacilitates responses using written, mouse-based, tablet-based or voiceentry such as multiple choice, true or false, or pull-down menuselections. In other embodiments, the questions may require free entrysuch as by writing, voice dictation, or keyboard entry. In theseexamples, the patient interface 250, the office interface 210, or theencounter module 200 may be configured to interpret electronic forms ofthese inputs, such as electronic writing or voice dictation.

In one embodiment, the history portion of the encounter may be comprisedof a standard series of questions. In another embodiment, the series ofquestions may be based on, for example, a preference specified by theprovider, the patient's diagnosis, the patient's symptoms or some otherunique aspect of the encounter.

In still another embodiment, the history portion of the encounter can becomprised of questions from a database whereby the next question to beasked can be determined, for example, based on an answer to a previousquestion. This dynamically-traversed database of questions may useanswers from a question to determine subsequent questions to ask or todetermine sets of questions to ask based on a tree organization ofquestions in the database. For example, if a patient reports colorvision loss, the system can be configured to add a series of questionsrelated to color vision loss to its list of questions even if they werenot previously included in the set of questions to be asked. In laterquestioning, it the patient reports pain on eye movement, the system canbe configured to add, for example, questions related only to pain on eyemovement or questions related to pain on eye movement and color visionloss. The dynamic allocation of new questions based on answers toprevious questions can be configured such that a provider can allow ordisallow such a feature.

In one embodiment, a dynamically-traversed electronic questionnaire canbe configured to assign priority values to each question so that certainquestions can be asked before other questions. In still anotherembodiment, the system can provide a running count of the total numberof questions to be asked to the patient along with an estimated totaltime to completion. In related embodiments, the system can be configuredto allow users or providers to shorten the questionnaire, such as byexcluding lower priority questions, based on aspects of the dynamicquestionnaire such as it taking too much time or involving too manyquestions and answers.

In another embodiment, the patient interface 250 can be configured toallow the user to change display parameters, such as size, color andfont type, used to display questions with the patient interface 250. Inother embodiments, the patient interface 250 can be configured to readquestions aloud, for example using a text-to-speech system orpre-recorded voices, or to ensure privacy by providing a headphone jackwhere the user can connect headphones.

In one embodiment, the encounter module 200 can be configured to directdevices 260 to perform tests and store results associated with theclinic process 205 and the patient's information contained within theencounter module 200. The encounter module 200 can be configured tocommunicate with these devices 260 using a direct wired connection, suchas a USB, Ethernet or serial connection, a wireless connection, such asBluetooth® or 802.11, an intermediate electronic device, such as a USBkey, memory card or patient interface 250, or a physical codedembodiment such as a bar code or QR code.

In one embodiment, the encounter module 200 or patient interface 250 canbe configured to alter the list of tests requested for an encounterbased on answers to history questions or results from testing on devices260. The encounter module 200 or the patient interface 250 can also beconfigured to direct a device 260 to conduct a new test or tests inaddition to or in place of the old test or tests. Alteration of theclinic process 205 by the encounter module 200 or patient interface 250can be allowed or disallowed by a provider either globally orspecifically, such as based on answers to specific questions orcategories of questions, using, for example, the office interface 210.

In one embodiment, the encounter module 200 or the patient interface 250can be configured to initiate operation of a device 260, such as aninstrument to measure vision. In another embodiment, the encountermodule 200 or the patient interface 250 can be configured to allow theuser to initiate operation of a device 260, such as by saying “ready,”pushing a button or pressing a pedal that may be attached to the patientinterface 250. In still another embodiment, the encounter module 200 orthe patient interface can be configured to allow the user to initiateoperation of the device 260, such as by saying “ready,” pushing a buttonor pressing a pedal, through the device 260.

As discussed previously, the encounter module 200 or the patientinterface 250 can be configured to receive data, such as examinationresults, from devices, such as the tracking system 240, the patientinterface 250, or devices 260. As discussed above, the encounter module200 can be configured to communicate with these other components using,for example, a wired connection, a wireless connection, an intermediateelectronic, or using a physical embodiment.

Collection of data from numerous devices by the patient interface 250 orencounter module 200 can be particularly advantageous by reducingtranscription or sorting errors that can occur when human laborers areinvolved in these processes or by centralizing all encounter data in onelocation.

Various components in the electronic encounter system, such as theencounter module 200, can be configured to compile encounter data into adigital package or packages that can be uploaded to, for example, anelectronic health record system either in the office, such as the officedatabase 220, or outside the office via secure external communication235, transmitted to other individuals on a patient's healthcare team viasecure external communication 235, reviewed directly by the provider ona patient interface 250 or office interface 210, or stored on anaccessible external database 230. The external database 230 can beconfigured to be accessible remotely, such as via the Internet, forexample, to facilitate sharing of exam data between providers or tofacilitate access by the patient to their own healthcare data.

As discussed previously, the encounter module 200 can be configured totrack both patients and clinic personnel using the tracking system 240.The encounter module 200 can be configured to store tracking informationsuch that it, for example, can be viewed or analyzed using an officeinterface 210. By tracking a patient's location over time, the encountermodule 200 can be configured to develop clinic patient flow maps thatmay enable staff to identify both acute and chronic problems with clinicflow. For instance, identification of a patient by the encounter module200 who has been waiting longer than a pre-defined threshold valuestored in a clinic process 205 can alert the staff, for example via anoffice interface 210, to address problems with that patient's encounterthat might be leading to this delay. Identification of chronicbottlenecks and waiting points across numerous encounters can allowpractices to optimize their workflow.

Providers can be tracked in several ways. In one embodiment, mobileoffice interfaces 210 can be configured with tracking systems 240 toidentify the location and identity of providers carrying them. Inanother embodiment, the patient interface 250 can be configured torequire providers to log in whenever they are consulting with a patient.In still another embodiment, the tracking system 240 can be configuredto monitor the location or identity of providers wearing identifiers,such as RFID tags. In other embodiments, the encounter module 200 couldbe configured to communicate updates to patients, such as by using thepatient interface 250, to, for example, estimate the approximate waittimes until the provider sees them or to convey how many patients stillneed to be seen by the provider before they are seen by the provider.

The electronic encounter portal can also be configured to provideentertainment or education to a patient. For example, the patientinterface 250 can be configured to provide Internet access 235, accessto previous encounter records stored on the encounter module 200, oraccess to previous encounter records stored on the external database230. The patient interface 250 can also be configured to provide accessby the patient to educational resources, potentially targeted toward thediagnosis or future treatments for a patient that may be stored oncomponents such as the encounter module 200. In one embodiment, theprovider can use a patient interface 250 or an office interface 210 toenter orders for an educational program into a clinic process 205.

In another embodiment, the patient interface 250 can be used to inform apatient about clinic resources, such as clinical trials, supportprograms, therapeutic services, restrooms, refreshments, etc. based oninformation stored on the encounter module 200. The encounter module 200can also be configured to direct patients to these resources, such asrestrooms, based on information from the tracking system 240 andrequests from the patients using the patient interface 250. Theencounter module 200 can also be configured to manage communicationsbetween patients, using a patient interface 250 and office staff, suchas by using an office interface 210.

In one embodiment, the patient interface 250 can be configured to storedata from devices and, in an embodiment that is mobile such as a tabletor smartphone, can allow the patient to transport encounter data throughthe clinic process 205 for review by or with the provider. In anotherembodiment, the office interface 210 can be configured to enable data tobe uploaded for review by the provider. Both the patient interface 250and the office interface 210 can be configured to access and use priorvisit data from the encounter module 200 to enhance assessments of apatient's healthcare status. Similarly, both the patient interface 250and the office interface 210 can be configured to access prior data fromthe external database 230 to enhance assessments of a patient'shealthcare status.

In related embodiments, the encounter module 200 and the externaldatabase 230 can be configured to act as common locations for encounterdata that can be accessed by both patients and providers. The externaldatabase 230 can be configured to allow remote access to encounter databy both providers and patients when they are outside of the office.Similarly, the external database 230 can be configured to receive datafrom devices 260 at locations outside of the described office and sharethese results with the encounter module 200 for example, to enableautomated remote healthcare encounters.

In one embodiment of an electronic encounter portal, a check-outprocedure 420 may be the last order or step in a clinic process 205. Invarious embodiments, the office interface 210 or the patient interface250 can be configured to allow providers to enter orders for futureencounters such as testing or therapies. In other embodiments, theoffice interface 210 can be configured to enable the provider to enterbilling information to be submitted for insurance reimbursement ordirectly charged to the patient. In still another embodiment, the officeinterface 210 can be configured to allow the provider to recommend afollow-up interval for the next encounter. In a related embodiment, theoffice interface 210 or the patient interface 250 can be configured toallow the patient to select the best time and data for a follow-upencounter. In another embodiment, the office interface 210 can beconfigured to allow the provider to order educational materials oreducational sessions for the patient that may occur after the encounterconcludes.

Accordingly, various embodiments described herein can reduce the needfor clinic personnel to perform these tasks. In addition, variousembodiments enable users to conduct their own complete eye exams.

Automated Eye Examination

FIG. 12 shows an example of a binocular eye examination system based onoptical coherence tomography. Component 500 may be comprised of the mainelectronics, processors, and logic circuits responsible for control,calculations, and decisions for this optical coherence tomographysystem. Light can be output from light source 502, which may becontrolled at least in part by component 500. The light source may becomprised of a broadband light source such as a superluminescent diodeor tunable laser system. The center wavelength for light source 502 canbe suitable for optical coherence tomography of the eye, such as 840 nm,1060 nm, or 1310 nm. The light source 502 may be electronicallycontrolled so that it can be turned on, off or variably attenuated atvarious frequencies, such as 1 Hz, 100 Hz, 1 kHz, 10 kHz or 100 kHz. Inone embodiment, light from light source 502 can travel throughinterferometer 504, which may be comprised of a Mach Zender or othertype of interferometer, where a k-clock signal can be generated. Thiselectronic signal can be transmitted to electronics on component 500 orother components in the system and can be captured on a data acquisitionsystem or used as a trigger for data capture.

The k-clock signal can be used as a trigger signal for capturing datafrom balanced detectors 518 r and 518 l. Alternatively, the k-clocksignal can be captured as a data channel and processed into a signalsuitable for OCT data capture. This k-clock signal can be captured allof the time, nearly all of the time or at discrete times after which itwould be stored and recalled for use in OCT capture. In someembodiments, various parameters of the k-clock signal, such as frequencyor voltage, can be modified electronically, such as doubled orquadrupled, to enable deeper imaging in eye tissues. In variousembodiments with light sources that sweep in a substantially linearfashion, the k-clock can be removed and a regular trigger signal may beemployed. In various embodiments, the trigger signals used byelectronics 595 r and 595 l may be synchronized with other components ofthe system, such as mirrors, variable focus lenses, air pumps andvalves, pressure sensors and flow sensors.

Most of the light, such as 90% or 95%, that enters the interferometer504 can be transmitted through interferometer 504 to a beam splitter orcoupler 510. As used herein, “coupler” may include splitters as well ascouplers. Beam coupler 510 can split the light from interferometer 504or light source 502 to two output optical paths, specifically right andleft, that lead directly to couplers 515 r and 515 l. Henceforth,designation of a device or component with a suffix of ‘r′’ or ‘l’ willrefer to two devices that may be of the same type but are located indifferent optical paths. For example, one component may be located inthe optical path of the right eye, designated as ‘r,’ and the other islocated in the optical path of the left eye, designated as ‘l.’

The optical paths in this system may be comprised of fiber optics, freespace optics, a mixture of free space and fiber optics. Othercombinations are also possible. The split ratio of coupler 510 can be apredefined ratio, such as 50/50 or 70/30. Light from coupler 510 cantravel to couplers 515 r and 515 l. Couplers 515 r and 515 l may alsosplit light from coupler 510 with a predefined split ratio such as a50/50, 70/30, or 90/10. The split ratios for couplers 510, 515 r, and515 l may be the same or different split ratios.

One portion of light from couplers 515 r and 515 l, such as 70%, cantravel to a so-called ‘reference arm’ for each of the right and leftoptical paths. The reference arm of a light path is distinguished fromthe so-called sample arm of the light path since light in the referencearm of the system does not interface with eye tissue directly whereaslight in the sample arm is intended to contact eye tissue directly.

The main component in the reference arm may be an optical delay device,labeled as 516 r and 516 l in the right and left optical paths of thesystem. Optical delay devices can introduce a delay, such as 1picosecond, 10 picoseconds, or 100 picoseconds, into a light path toenable matching of the overall path length of one optical path to theoptical path length of another light path. In various embodiments, thisoptical delay may be adjustable, such as with an adjustable free lightpath between two collimating optical devices, a fiber stretcher thatincreases or decreases the length of a fiber optic, or a fiber Bragggrating that delays light based on changes in the angle of incidence oflight.

In other embodiments, this optical delay line can include variableattenuators to decrease or increase the transmission of light, opticalswitches or mechanical shutters to turn the light off or on. Althoughpictured in the reference arm of this system, an optical delay line canalso be entirely included in the sample arm optical path for each eye orcontained in both the reference and sample arm light paths. Othercombinations of sample and reference light paths are also possible.

In one embodiment, light from optical delay devices 516 r and 516 l cantravel to couplers 517 r and 517 l where it may be combined with lightfrom the sample arm that has been transmitted from couplers 515 r and515 l. Couplers 517 r and 517 l may combine light from two light pathswith a predefined ratio between paths such as a 50/50, 70/30, or 90/10.Light from couplers 517 r and 517 l may travel through two outputs fromcouplers 517 r and 517 l to balanced detectors 518 r and 518 l where thelight signal can be transformed into an electrical signal, for examplethrough the use of photodiodes configured to detect the light input fromcouplers 517 r and 517 l.

The electrical signal generated by balanced detectors 518 r and 518 lcan be in various ranges, including but not limited to −400 mV to +400mV, −1V to +1V, −4V to +4V and have various bandwidths, including butnot limited to 70 MHz, 250 MHz, 1.5 GHz. The electrical signal frombalanced detectors 518 r and 518 l may travel via an electricalconnection, such as a coaxial cable, to electronics 595 r and 595 lwhere it can be captured by a data acquisition system configured tocapture data from balanced detector devices. Although not pictured here,a polarization sensitive optical component can be disposed beforebalanced detectors 518 r and 518 l to split two polarities of light in asingle light path into two optical paths. In this embodiment, twooptical paths leading to balanced detectors 517 r and 517 l would besplit into a total of four optical paths, which would lead to twobalanced detectors on each side.

One portion of light from couplers 515 r and 515 l, such as 30% or 50%,can travel to a so-called sample arm of each of the right and leftoptical paths. In various embodiments, the system may be configured totransmit the light through fiber optic cable or through free spaceoptics. Light from couplers 515 r and 515 l can travel to optics 520 rand 520 l, which may be collimators configured to collimate the lightfrom couplers 515 r and 515 l. Light from optics 520 r and 520 l cantravel to lens systems 525 r and 525 l, which may be comprised of fixedfocus or variable focus lenses.

In various embodiments, these lenses can be fabricated from plastic orglass. In other embodiments, these lenses may be electrowetting lensesor shape-changing lenses, such as fluid-filled lenses, that can varytheir focal distance based on internal or external control mechanisms.In one embodiment, variable focus lenses in lens systems 525 r or 525 lmay have their focal length modified by electrical current or voltageapplied to lens systems 525 r or 525 l. This control may come fromelectrical components 595 r and 595 l and the parameters of this controlmay be based on pre-determined values or may be derived during operationof the system based on input received from other components of thesystem.

The lenses in lens systems 525 r and 525 l can be configured to haveanti-reflective coatings, embedded temperature sensors, or otherassociated circuitry. Lens systems 525 r and 525 l may be comprised of asingle lens or multiple lenses. The lenses comprising systems 525 r and525 l may be present at all times or may be mechanically moved in andout of the light path such as by an attached motor and drive circuitunder electrical control from components 595 r and 595 l. Configurationof lens systems 525 r and 525 l to be moveable can enable imaging atdifferent depths in an eye tissue by introducing and removing vergencein the optical system.

Light from lens systems 525 r and 525 l can travel to movable mirrors530 r and 530 l. Movable mirrors 530 r and 530 l may be comprised ofMEMS (microelectromechanical systems) mirrors, controlled bygalvanometers, or moved by other means. Movable mirrors 530 r and 530 lcan be comprised of a single mirror that reflects light across 2 axes,such as X and Y, can be comprised of a single mirror that reflects lightacross one axis only, or can be comprised of two mirrors that eachreflect light across one axis only said axes being substantiallyperpendicular to each other.

Electrical control of mirrors 530 r and 530 l, which may control eachaxis of reflection independently, can be provided by components 595 rand 595 l. The electronic control of mirrors 530 r and 530 l may beconfigured to enable variable amplitude deflections of mirrors 530 r and530 l. For example, for a given drive frequency in a given axis, thecurrent or voltage applied to mirrors 530 r and 530 l may enable largeror smaller amplitude deflections of the mirror surface, thus creating azoom effect where the created image can be made smaller or larger.

Light that has been reflected from movable mirrors 530 r and 530 l cantravel to lens systems 535 r and 535 l. Lens systems 535 r and 535 l maybe fixed or variable focus lenses that are located in the optical lightpath at all times or only part of the time. Electrical control of lenses535 r and 535 l, can be conducted by components 595 r and 595 l and mayinclude for example moving these lenses in and out of the light path orchanging their focal lengths. Other actions are also possible.

Light from lens systems 535 r and 535 l can travel to optics 540 r and540 l, which may be comprised of dichroic mirrors or couplers. Optics540 r and 540 l may be configured to transmit light from lens systems535 r and 535 l and combine it with light from lens systems 545 r and545 l. Light from optics 540 r and 540 l can travel to eye pieces 542 rand 542 l before being transmitted to the right and left eye tissues.

Eye pieces (or oculars) 542 r and 542 l can be configured asmulti-element lens systems such as Ploessel-type eyepieces, Erfle-typeeyepieces, telescopes or other designs. In some embodiments, optics 540r and 540 l may be configured to be part of or inside of eyepieces 542 rand 542 l. In other embodiments, variable focus lenses orpolarization-sensitive optics and beam splitters can be configuredinside eyepieces 542 r and 542 l to enable wider axial focusing rangesin eye tissues or simultaneous focusing of light from two axiallocations in eye tissues. Eyepieces 542 r and 542 l may be configuredwith optical components without any refractive power, such as opticalwindows, that may be physically attached or separate from the otherlenses in the system.

Light entering the right and left eyes can be reflected back througheach optical path to enable optical coherence tomography. In oneembodiment, the path of back reflected light originating from lightsource 502 can travel from each eye to eyepiece 542 to optics 540 tolens system 535 to movable mirror 530 to lens system 525 to optics 520to coupler 515 to coupler 517 to balanced detector 518. Variouscalculations and logic-based processes can be completed by components595 r and 595 l based on data contained in signals received frombalanced detectors 518 r and 518 l.

As discussed previously, timing of capture of the signals received bycomponents 595 r and 595 l may be controlled by other inputs, such asthe k-clock input, dummy clock input, or other electrical signal.Electronics 500, 595 r, and 595 l may be configured to have digitalsignal processors (DSPs), field-programmable gate arrays (FPGAs), ASICs,or other electronics to enable faster, more efficient or substantiallyreal-time processing of signals received by components 595 r and 595 l.Electronics 500, 595 r, and 595 l may be configured with software, suchas a real-time operating system, to enable rapid decisions to be made bysaid components.

In various embodiments not illustrated here, the eye tissues may bereplaced by calibration targets that, for example, occlude theeyepieces, dispose a mirror target at various distances in front of theeyepieces, or provide an open air space for calibration. Electronics 500may be configured to control the introduction of these non-tissuetargets, such as when the eyes are not present in the optical system. Inother embodiments, electronics 500 may be configured to dispose poweredor moveable components of the system to various states, such as “off,”“home,” or “safety” at various times, such as the beginning, middle andend of a test.

Components 595 r and 595 l can also be configured to control lightsources 585 r-588 r and 585 l-588 l, which may be comprised of variouslight sources such as, for example, laser diodes, light emitting diodes,or superluminescent diodes. In the illustrated embodiment, only fourlight sources 585 r-588 r and 585 l-588 l are shown. In variousembodiments, different numbers of light sources 585 r-588 r and 585l-588 l may be used and different wavelengths of light sources may beused. In one embodiment, one each of a blue-colored, green-colored,red-colored and near infrared diode can be included in the light sourcegroups 585 r-588 r and 585 l-588 l.

In other embodiments, light sources 585 r-588 r and 585 l-588 l may becomprised of tunable light sources capable of producing numerous spectraof light for the purposes of hyperspectral imaging. For example,employing various light sources in the visible spectrum capable ofproducing narrow bands of light centered at characteristic peaks ofabsorption or reflectivity for oxyhemoglobin and deoxyhemoglobin can beused to enable hyperspectral imaging. Similarly, numerous individuallight sources can be used to achieve the same effect as a light sourcewith a tunable wavelength.

These light sources can be configured to be controlled by components 595r and 595 l using, for example, pulse-width modulation, currentmodulation, voltage modulation, or other electrical control means. Inone embodiment, the modulation frequency of at least one light sourcecan be modified to correct for chromatic aberration from the opticsbetween the light sources and the eye. For example, the modulationfrequency of the red channel could be variably increased or decreased indifferent mirror positions to account for lateral chromatic spreadbetween the red light source and other colors such as blue or green.

Light from light sources 585 r-588 r and 585 l-588 l can travel tooptics 580 r-583 r and 580 l-583 l that may, for example, be focusingoptics. Light from optics 580 r-583 r and 580 l-583 l can then travel tooptics 575 r-578 r and 575 l-578 l that may, for example, be focusingoptics. Each path of light can contain a single frequency of light, suchas 450 nm, 515 nm, 532 nm, 630 nm, 840 nm, or 930 nm or multiplefrequencies of light.

Each path of light from light sources 585 r-588 r and 585 l-588 l may bereflected off optics 571 r-574 r and 571 l-574 l which may, for example,be dichroic mirrors or couplers and may be specifically configured toreflect and transmit light based on their position in the optical path.For example, one optic may be configured to transmit light with awavelength less than 500 nm and reflect light with a wavelength greaterthan 500 nm.

Optics 571 r-574 r and 571 l-574 l can be configured to join togetherlight from different light sources 585 r-588 r and 585 l-588 l into asingle, substantially coaxial beam of light that can travel to optics561 r and 561 l. Optics 561 r and 561 l may be dichroic mirrors orcouplers and may be configured to have a pre-defined split ratio oflight entering from different directions or having differentwavelengths, such as 90/10, 50/50, and 10/90.

A portion of light from optics 571 r-574 r and 571 l-574 l can betransmitted through optics 561 r and 561 l to sensors 566 r and 566 lwhich may, for example, be photodiodes or other components capable ofsensing light. Signals from sensors 566 r and 566 l can be configured tobe transmitted along electrical connections between sensor 566 r andelectrical component 595 r on the right side and sensor 566 l andelectrical component 595 l on the left side. In one embodiment, sensors566 r and 566 l can be configured to monitor the total light power beingemitted by light sources 585 r-588 r and 585 l-588 l.

The portion of light reflected off optics 561 r and 561 l from optics571 r-574 and 571 l-574 l can travel to lens systems 560 r and 560 l.Lens systems 560 r and 560 l may be comprised of fixed focus or variablefocus lenses. In various embodiments, these lenses can be fabricatedfrom plastic or glass. In other embodiments, these lenses may beelectrowetting lenses or shape-changing lenses, such as fluid-filledlenses, that may vary their focal distance based on internal or externalcontrol mechanisms.

In one embodiment, variable focus lenses in lens systems 560 r and 560 lmay have their focal length modified by electrical current or voltageapplied to the lens systems. This control may be under the direction ofelectrical components 595 r and 595 l and it may be based onpre-determined values or be derived during operation of the system basedon input received from other components of the system.

The lenses in lens systems 560 r and 560 l can be configured to haveanti-reflective coatings, embedded temperature sensors, or otherassociated circuitry. Lens systems 560 r and 560 l may be comprised of asingle lens or multiple lenses. The lenses comprising systems 560 r and560 l may be present in the light path at all times or may bemechanically moved in and out of the light path by an attached motor anddrive circuit under electrical control from components 595 r and 595 l.Configuration of lens systems 560 r and 560 to be moveable can enableimaging at different depths in an eye tissue by introducing and removingvergence in the optical system.

Light from lens systems 560 r and 560 l can travel to lens systems 555 rand 555 l. In some embodiments, lens systems 555 r and 555 l can belocated in their respective optical paths at all times. In otherembodiments, lens systems 555 r and 551 may be moved in and out of theoptical paths based on electrical signals from components 595 r and 595l.

Light from lens systems 555 r and 555 l can travel to movable mirrors550 r and 550 l. Movable mirrors 550 r and 550 l may be comprised ofMEMS mirrors, controlled by galvanometers, or moved by other means.Movable mirrors 550 r and 550 l can be comprised of a single mirror thatreflects light across 2 axes, such as X and Y, can be comprised of asingle mirror that reflects light across one axis only, or can becomprised of two mirrors that each reflect light across one axis onlysaid axes being substantially perpendicular to each other.

Electrical control of mirrors 550 r and 550 l, which can control eachaxis of reflection independently, can be provided by components 595 rand 595 l. Mirrors 550 r and 550 l may have one axis of fast resonantmovement, one axis of slow resonant movement, two slow axes of movement,one fast resonant axis and one slow axis of movement, or two fastresonant axes of movement.

The electronic control of mirrors 530 r and 530 l may be configured toenable variable amplitude deflections of mirrors 530 r and 530 l. Forexample, for a given drive frequency in a given axis, the current orvoltage applied to mirrors 530 r and 530 l may enable larger or smalleramplitude deflections of the mirror surface, thus creating a zoom effectwhere the created image can be made smaller or larger.

Light from movable mirrors 550 r and 550 l can travel to lens systems545 r and 545 l. Lens systems 545 r and 545 l may be configured tointroduce variable amounts of optical cylinder power into the opticallight paths. In one embodiment, the magnitude and axis of thecylindrical optical power introduced into the optical paths by lenssystems 545 r and 545 l can be configured to correct an astigmatismpresent in an eye interfacing with this system.

Lens systems 545 r and 545 l can comprised of two cylindrical lensesconfigured to counter-rotate and co-rotate with each other, anelectrically controlled variable focus, liquid filled lens, or othermethod of introducing cylindrical optical power into a light path.Although not illustrated here, lens systems 545 r and 545 l can also belocated between mirrors 530 r and 530 l and optics 540 r and 540 l inthe OCT light path.

Light from lens systems 545 r and 545 l can travel to optics 540 r and540 l where it may be reflected to combine with light originating atlight source 502. In one embodiment, an exit pupil expander can bedisposed between moveable mirrors 550 r and 550 l and the eye tissues toincrease the size of the exit pupil created at the eye tissue by mirrors550 r and 550 l.

Light from lens systems 545 r and 545 l may be transmitted througheyepieces 542 r and 542 l after which it may enter the right and lefteyes of a subject. Light transmitted through eyepieces 542 r and 542 lcan be configured to be seen by the subject as organized light, such asin a retinal scanning display system, can be configured to be seen bythe subject as video-rate imaging through modulation of light sources585 r-588 r and 585 l-588 l by components 595 r and 595 l, or can beconfigured to broadly stimulate the eye with light such as formeasurements of pupillary reactions to light stimuli.

Light from lens systems 545 r and 545 l can also be configured toreflect back out of the eye and through eyepieces 542 r and 542 l, offoptics 540 r and 540 l, through lenses systems 545 r and 545 l, offmoveable mirrors 550 r and 550 l, through lens systems 555 r, 555 l, 560r, and 560 l and then through optics 561 r and 561 l. Light transmittedthrough optics 561 r and 561 l can be detected by sensors 567 r-570 rand 567 l-570 l that may, for example, be comprised of photodiodes.

In various embodiments, this light is split into predefined wavelengthbands, such as 440 nm-460 nm, 510 nm-580 nm, 625 nm-635 nm, or 930 nm,by dichroic mirrors 562 r-565 r and 562 l-565 l. In other embodiments,separation of light from optics 561 r and 561 l into bands can beachieved by the use of filters that selectively transmit or reflectwavelength bands of interest.

In still other embodiments, separation of light from optics 561 r and561 l into bands can be achieved by configuring the system with sensors567 r-570 r and 567 l-570 l that only produce electrical signals inspecifically targeted bands, such as 400-500 nm, 600-800 nm or >900 nm.Electrical signals from sensors 567 r-570 r and 567 l-570 l can travelto components 595 r and 595 l across electrical connections to enableimaging of tissues in the eye by sensing the light originating at lightsources 585 r-588 r and 585 l-588 l back reflected in desired wavelengthbands.

FIG. 13 shows an example of a display of eye examination data on anelectronic device 600. In some embodiments, the display system enablesviewing and comparing of data from two eyes of one patient acrossmultiple tests and dates in a minimal amount of space. Accordingly, someembodiments enable the user to collapse undesirable test or date fieldsso as to maximize the display area of desired measurements.

Device 600 may be a portable computing platform, such as a smartphone ora tablet, or be a stationary computing platform with a display screen.Device 600 may allow touch screen operation, eye tracking operationwhere eye movements are interpreted as cursor movements on the device600 itself or operation with standard computing peripherals such as amouse and keyboard.

Data in the illustrated grid can be populated by software from adatabase of examination data that may, for example, include exams frommany patients on many days. Accordingly, software running on device 600can be configured to enable searching or selection of the patient whoseexam data is to be displayed in the illustrated display configuration.

Software on device 600 can be configured to output exam data in asubstantially tabular format comprised mainly of rows 612 and columns614. In various embodiments, the software can be configured to includeall exam data for a given date in one column 614 while all measurementsfrom a given test can be included in a single row 612. The software canalso enable preferences that allow transformation of this rule such thatdates are in rows 612 and tests are in columns 614. In some embodiments,each box in the table representing an intersection of a row 612 and acolumn 614 can be represented as a field populated with, for example, anumerical measurement, a text value, or an image. Although the fieldsare labeled generically in FIG. 6, it will be appreciated that a varietyof data, such as numbers, text, or images, can be displayed in eachfield.

Field 610 can be configured to contain information on the patient, suchas name, date of birth, medical record number, age, gender. Although notillustrated here, field 610 may also be used to open pop-up windows thatcan be used to search or configure the exam display system.

Fields 620-625 can be configured to contain dates of exams for a givenpatient. In one embodiment, clicking of a column heading 620-625 togglesthe column between collapsed and expanded configurations where data isnot displayed in the collapsed configuration but data is displayed inthe expanded configuration. In FIG. 6, columns 620, 623 and 625demonstrate expanded fields while columns 621, 622 and 624 representcollapsed fields. Thus, the fields in the collapsed columns 621, 622,624 may be collapsed. For example, fields 650, 651, 652, 653, 654 may becollapsed when column 621 is collapsed. The software can be configuredto allow users to toggle this display setting with, for example, asimple click of a column heading or other selection process.

Fields 630-634 can be configured to contain individual tests conductedon a given patient. In one embodiment, clicking of a row heading 630-634toggles the row between collapsed and expanded configurations where datais not displayed in the collapsed configuration but data is displayed inthe expanded configuration. In FIG. 6, rows 631 and 634 demonstrateexpanded fields while rows 630, 632 and 633 represent collapsed fields.Thus, the fields in the collapsed rows 630, 632, 633 may be collapsed.For example, fields 640, 650, 660, 670, 680, and 690 may be collapsedwhen row 630 is collapsed. The software can be configured to allow usersto toggle this display setting with, for example, a simple click of arow heading or other selection process.

In FIG. 13, it can be appreciated that two special rows can existcorresponding to the right (OD) and left (OS) eye headings. The softwarecan be configured to collapse or expand all tests for a given eye whenthat row heading, such as OD or OS, is clicked or otherwise selected.

Referring to FIG. 13, fields 641, 644, 671, 674, 691, and 694 can beconfigured to display data, such as numbers, text or images. In oneembodiment, display of images in these fields enables the user to clickon the images to bring up a larger window in which to view the images.In another embodiment, display of numbers in these fields enables theuser to click on the numbers to bring up a graph of the numbers, such asgraph over time with the dates in the column headers as the x-axis andthe values in the rows as the y values.

The software can be configured to show collapsed fields (e.g. field 640,650, 660, 651, 661) in a different color or in a different size. Thesoftware can also be configured to display scroll bars when fieldsextend off the display screen. For example, if more tests exist in thevertical direction than can be displayed on a single screen, thesoftware can be configured to allow panning with finger movements orscrolling with, for example, vertical scroll bars. The software can beconfigured to enable similar capabilities in the horizontal direction aswell.

As described above, in some embodiments, a mask 100 is configured to beinterfaced with an ophthalmic device for performing an eye exam on apatient. In some embodiments, the ophthalmic device comprises an opticalcoherence tomography (OCT) device such as described above. An OCT deviceis operable to direct an incident light beam onto a patient's eye andreceive a reflected or scattered light beam from the patient's retina.Three-dimensional images of eye tissue, such as the cornea, iris, lens,vitreous, or retina may be obtained by measuring reflected or scatteredlight from the tissue for example using Optical Coherence Tomography orother instruments. Many OCT devices employ beam-steering mirrors, suchas mirror galvanometers or MEMS mirrors, to direct the light beam to anobject of interest. Various OCT instruments comprise interferometersincluding light sources and optical detectors or sensors that receivelight reflected or scattered from the eye and produce a signal usefulfor imaging the eye. One example of an OCT device is described abovewith reference to FIG. 12.

When the mask 100 is interfaced with an OCT device for performing an eyeexam, an incident light beam is transmitted through at least one of theoptically transparent sections 124 of the mask 100 before impinging onthe retina of the eye. A portion of the incident light beam may bereflected by the optically transparent sections 124 of the mask. Suchreflection is undesirable as it decreases the amount of lighttransmitted to the retina of the eye and the reflected portion of theincident light beam may also reach the OCT device (e.g., the opticaldetector 518 therein) and may obscure the signal of interest, namely thereflected or scattered light from the retina. In some embodiments, toameliorate this problem, the optically transparent sections 124 of themask 100 are coated with an anti-reflective coating configured to reducereflection of the incident light beam by the optically transparentsections 124. In various embodiments, the optical transparent sections124 of the mask are configured to increase or maximize transmission oflight, such as from an OCT device, and the proximal portions 154 andconcaved rear surface 122 is configured to reduce or minimizetransmission of light, such as ambient light or light not emanating froman OCT machine and may be opaque and include opaque sides. For example,the proximal portions 154 may have sides that are substantiallynon-transmissive to visible wavelengths. These sides may for exampleblock 80-90%, 90-95%, 95-99%, and/or 99-100% of ambient visible light.Reduction of ambient light may for example assist in keeping thepatients pupils dilated. Conversely, the optically transparent sectionsmay have a transmittance of 70-80%, 80-90%, 90-95%, 95-99%, and/or99-99.5%, or 99.5%-100% or any combination of these ranges in thewavelength range at which the ophthalmic device operates such as at 450nm, 515 nm, 532 nm, 630 nm, 840 nm, 930 nm, 1060 nm, 1310 nm or anycombination thereof or across the visible wavelength range, near IRwavelength range, or both these ranges or at least 10%, 20%, 30%, 40%,500%, 60%, 70%, 80%, or 90% of the visible range, near IR range, orboth. In some embodiments, material (treated or untreated) such asplastic that is not substantially transparent to visible light or tomany visible wavelengths but is transparent to infrared light may beemployed, for example, as the window to the mask and possibly for atleast part of the proximal portion (e.g., the sides). The window wouldthus potentially be able to transmit an IR probe beam from theophthalmic device (e.g., OCT or SLO instrument) yet could block ambientvisible light or a significant portion thereof thereby allowing theuser's pupils when wearing the mask to be more dilated. In variousembodiments, however, having a window having at least some wavelengthsin the visible be transmitted through is useful for the wearer. Incertain embodiments, the ophthalmic device operates at one or more nearinfrared wavelength. For example, the probe beam is in the nearinfrared. The window may therefore be transparent in at least at the NIRwavelength(s) at which the ophthalmic device operate, for example, atthe probe wavelength. Optical coatings may be employed to impart thesespectral characteristics on the mask (e.g., on the window).

In some embodiments, the anti-reflective coating is configured to reducereflection of the incident light beam in a wavelength range that iscomparable to the wavelength range of the light source used in the OCTdevice. For example, wide-spectrum sources such as superluminescentdiodes, ultrashort pulsed lasers, swept source lasers, very shortexternal cavity lasers, vertical cavity surface emitting lasers, andsupercontinuum lasers can be used in OCT devices and could be used inother ophthalmic diagnostic and/or treatment devices. These lightsources may operate in the visible and/or near infrared. For example,light sources that emit light in visible wavelengths such as blue,green, red, near infrared or 400-1500 nm may be used to image the eye.Accordingly, in some embodiments, the anti-reflective coating isconfigured to reduce reflection of the incident light beam in awavelength range that is comparable to a visible spectrum. In someembodiments, the anti-reflective coating spans both a visible andinvisible wavelength spectrum, operating at wavelengths such as 400 nmto 1500 nm, 450 nm to 1150 nm, 515 nm to 1100 nm or other regions. Theanti-reflective coating may be strongly wavelength dependent or may belargely wavelength independent. Likewise, the anti-reflective coatingmay reduce reflection over a wide or narrow band. In some embodiments,the anti-reflective coating is configured to reduce reflection of theincident light beam in a wavelength band having a bandwidth ranging fromabout 5 nm to about 200 nm. In some embodiments, for example, thisbandwidth may be between about 5 and 50 nm, 50 and 100 nm, 100 and 150nm, 150 and 200 nm, 200 and 250 nm or larger. In some embodiments, theAR coating may operate across multiple bands that are separated fromeach other. Each of these bands may, for example, have a bandwidth, forexample, as described above. The antireflective coating may reducereflections at a normal incident angle to between about 5-10%, 3-5%,1-3% or less. For example, with the anti-reflective coating, reflectionsat a normal incident angle may be reduced to 1 to 2% reflection, 0.5% to1% reflection or 0.1% to 0.5% reflection, or 0.05% to 0.5% reflection,or 0.1% to 0.5% reflection, 0.1% to 0.01% reflection, or combinationsthereof. In some embodiments, the amount of reflection may be higher orlower. In various embodiments, the anti-reflective coating operates onlight from normal incidence up to oblique angles of incidence such as±15 degrees, ±30 degrees or ±45 degrees.

The anti-reflective coating may comprise a multi-stack optical structureand, in particular, may comprise an interference coating such as aquarter-wave stack. The anti-reflective coating may comprise, forexample, one or more layers having a thickness of a quarter or halfwavelength of the light and accomplish reflection reduction throughdestructive interference. Other types of anti-reflection coatings may beemployed.

FIG. 14 illustrates a mask 200 for performing an eye exam according toan embodiment. The mask 200 includes a distal sheet member (distalportion) 218 and a proximal member (proximal portion) 254 coupled to thedistal portion 218. The distal portion 218 has one or more substantiallyoptically transparent sections 224. The proximal portion 254 has a rearsurface 222 that faces the patient's face when in use, and is configuredto conform to contours of the patient's face and align the one or moresubstantially optically transparent sections 224 of the distal portion218 with the patient's eyes. The distal portion 218 can be configured tobe optically interfaced with a docking portion of an ophthalmic devicesuch as an OCT instrument. The ophthalmic device is operable to directan incident light beam such as a probe beam onto and/or into a patient'seye and receive a reflected or scattered light beam from the patient'seye. The docking portion of the ophthalmic device includes an opticalinterface such an optically transparent window or plate for transmittingthe incident light beam therethrough and incident on the opticallytransparent sections 224 of the distal portion 218. The docking portionmay also include a slot in which a flange on the mask fits into. In someembodiments, the ophthalmic device comprises an optical coherencetomography device although the ophthalmic device may comprise otherdiagnostic instruments or devices such as a scanning laserophthalmoscope (SLO).

In some embodiments, to reduce retro-reflection back into the ophthalmicdevice, at least one of the optically transparent sections 224 of themask has at least a portion thereof that is tilted or sloped withrespect to the incident light beam when the distal sheet member 218 isoptically interfaced with the docking portion of the ophthalmic device.In such embodiments, the incident light beam forms a finite (non-zero)angle of incidence with respect to the corresponding portion of themask. If the finite angle of incidence is sufficiently large, aretro-reflected light beam may be prevented from being retro-reflectedback into the oculars of the ophthalmic device. In some embodiments, themagnitude of the tilt or slope angle is in a range from about 1 degreeto about 30 degrees. In some embodiments, the magnitude of the tilt orslope angle is greater than about 1 degrees, 2 degrees, 4 degrees, 5degrees, 6 degrees, 8 degrees, 10 degrees, 15 degrees, 20 degrees, 25degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55degrees, and less than 60 degrees, 55 degrees, 50 degrees, 45 degrees,40 degrees, 35 degrees, 30 degrees, 25 degrees, 20 degrees, 15 degrees,10 degrees, or 5 degrees or any combination thereof. For example, themagnitude of the slope may be greater in magnitude than 30° and lessthan 35° or greater than 10 in certain portions and less than 35° or40°. This tilt or slope angle may be measured between a central axisthrough the optical path from the ophthalmic device (e.g., OCTinstrument) to the mask and the normal to the surface of the opticallytransparent section 224 of the mask where that central axis or probebeam is incident. In some embodiments, this angle may be measured, forexample, with respect to the optical path from the ophthalmic device(e.g., OCT or SLO instrument) or optical axis of the ophthalmic devices,for example, from the exit pupil of left or right channel of the OCT orSLO instrument, an optical axis of an optical element (e.g., left and/orright ocular lens, eyepiece, or channel) associated with an ophthalmicdevice through which the beam passes prior to output from the ophthalmicdevices, as well as from a normal to a transparent interface (e.g., awindow or ocular lens) on the ophthalmic device. In addition, this anglemay be measured with respect to the normal to the surface on theoptically transparent section 224 of the mask where the beam or centerthereof or central axis therethrough from the ophthalmic instrumentwould be incident on the optically transparent section 224. Similarly,this angle may be measured with respect to the mask's forward line ofsight when worn or the line of sight of a wearer of the mask. A standardanatomical head form such as an Alderson head form may be used todetermine the line-of-sight through the mask. Accordingly, the angularranges described above may be measured between the line-of-sight of aAlderson head form when the mask is placed on the head form as would beworn by a wearer (in the as worn position) and the normal to the surfaceof the optically transparent section 224 of the mask at the locationthat the normal line-of-sight of the head form intersects or passes.Other approaches to measuring the angle may also be used.

In various embodiments, the shape of the rear surface 222 is determinedfrom measurements taken from at least one magnetic resonance imaging(MRI) scan of a human head. Segmentation of the surface of one or morefaces (e.g., at least 10, 20, 30, 100, to 200, 500, 1000, or more faces)obtained from MRI images can be used to determine a contour that issubstantially conformed to by the rear surface 222. Statisticalprocesses can be applied to these sets of MRI images to produce averageface contours, median face contours, or face contours that match acertain percentage of the population, such as 95%, 99° %, or 99.5%.These MRI images can also be used to define the line-of-sight throughthe mask. Standard lines defined by MRI images of the human head, suchas the eye-ear line extending from the center of the ear canal to thelateral canthus where the eyelids join or a line in the Frankfurt planeextending from the center of the ear to the lowest portion of the eyesocket, can be used to define the direction of the line-of-sight throughthe mask with a rear surface 222 defined by these same MRI images. Otherlines, such as a line that connects the pupillary center and macularcenter as seen by MRI could also be used. The placement of theline-of-sight on the optical transparent section 224 may also be definedby measuring the distance between the pupils, the interpupillarydistance (IPD), on the MRI images.

In various embodiments, the probe beam raster scanned across the tissueto obtain OCT signals over a region of the eye. As described above, toaccomplish such raster scanning, the direction of the probe beam may beswept using, for example, a MEMS mirror. FIG. 15A illustrate anarrangement where a probe beam is reflected off a beam steering mirrorthrough the mask window into the eye. The beam steering mirror can berotate back and forth to sweep the beam through a range of angles andthrough a range of positions in and/or on the tissue being images orevaluated. FIG. 15A show both the optical path of the probe beam as wellfor light scattered from the tissue that returns back through the OCTinstrument. As discussed above, in some instances, reflections from themask window are retro-reflected and thus also return to the sensors usedin the OCT instrument. With the normal to the window oriented at 00 withrespect to the incident probe beam, light is reflected from the windowback into the OCT instrument as shown in FIG. 15A. This retro-reflectedlight introduces noise into the signal comprising scatters light fromthe tissue, which could be a weak signal. The back reflection thusdecreases the signal to noise ratio and makes obtaining an image moredifficult.

To improve the signal to noise ratio, the window can be tilted an anglewith respect to the beam. This tilt angle may be β degrees. The resultis that the retro-reflected beam will be tilted such that the beamcannot enter back into the OCT instrument disrupting the signal. Asillustrated in FIG. 15B, for a given ophthalmic instrument such as anOCT instrument, there is an angle, Δ, of the retro-reflected beam(measured with respect to the incident beam or the incident opticalpath) at which the reflected beam is unlikely to not enter back into theOCT instrument and introduce noise onto the OCT signal. This angle Δ maydepend in part on the beam size, the size of the optics in the OCTinstrument, e.g., the beam steering mirror, as well as the relativelocation of the optics longitudinally along the optical path. This anglemay be for example, 0.50 to 1°, 1° to 2°, 2° to 3°, or combinationsthereof.

In various embodiments, as illustrated in FIG. 15C, the optics in theophthalmic instrument are configured such rays of light from the probebeam exiting the exit pupil or ocular of the ophthalmic instrument aregenerally converging. For example, the probe beam may substantially fillthe exit pupil of the ophthalmic instrument and be focused down. Suchapproach may be referred to as a flood illumination. In addition, asdescribed above, in some embodiments, a beam having a beam widthnarrower than the aperture of the ocular or exit pupil of the ophthalmicinstrument is swept through a range of angles. This approach may bereferred to as beam steering. In both cases, light rays may be incidenton the mask at a range of angles, for example, defined by a cone angle(α). This range of angles may be determined, for example, by theF-number or numerical aperture of the output of ophthalmic device suchas the ocular lens or focusing lens of the ophthalmic device and/or bythe movable mirror (MEMS mirror). This range of angles may alsocorrespond to the range of angles that the ophthalmic device willcollect light. For example, rays of light reflected back into this rangeof angles, may be collected by the ophthalmic instrument and contributeto the signal received. This collection angle may also be determined bythe F-number or numerical aperture of the ocular of the ophthalmicdevice (e.g., OCT instrument).

In some embodiments, the tilt or slope angle of the opticallytransparent section 224 of the mask is configured to be greater than thelargest angle of incident light produced by the OCT or other imaging orophthalmic device. For example, if an accompanying ophthalmic (e.g.,OCT) device, because of beam steering or flood illumination, produceslight rays between −30 degrees and +30 degrees with respect to theoptical axis of the ophthalmic device or with respect to the centralaxis of the optical path from the ophthalmic device to the mask (e.g., acone angle α of 30°), the magnitude of the tilt or slope angle (β) ofthe optically transparent section 224 of the mask can in variousembodiments be greater than the cone angle, for example, more negativethan −30 degrees or more positive than +30 degrees. For example, thetilt or slope angle, β, may be less than −30° (e.g., −31°, −32° etc.) orgreater than +300 (e.g., 31° or more).

FIGS. 15C-15E show how tilting the optically transparent section 224reduces the likelihood that light exiting the ophthalmic device will beretro-reflected back into the ophthalmic device.

FIG. 15C, for example schematically illustrates a planar window 224 onthe mask corresponding to the optically transparent section 224 thatdoes not have an AR coating. The window 224 is shown receiving a bundleof rays 265 of light that are focused down by a focusing lens 270 at theoutput of the ophthalmic device. This focusing element 270 may be a lens(e.g., in an ocular) that outputs a focused beam of light from theophthalmic device (e.g., OCT instrument). The focused bundle of rays 265is show centered about a central axis 267 of the optical path from theophthalmic device to the mask that corresponds to an optical axis 267 ofthe ophthalmic device (e.g., the optical axis of the focusing lens 270).The focused bundle of rays 265 may correspond to rays of lightsimultaneously provided with flood illumination or rays of light sweepthrough the range of angles over a period of time by the beam steeringoptics (e.g., movable mirror). FIG. 15C illustrate how, in either case,the bundle of rays 265 propagating along the optical path from theophthalmic instrument to the eye can be reflected back toward theophthalmic device at an angle within the collection angle defined by thenumerical aperture of the lens 270 such that this light would propagateback along the same path to the ophthalmic device and re-enter theophthalmic device possibly interfering with the signal.

FIG. 15D, for example schematically illustrates a planar window 224 onthe mask having an AR coating thereon. Accordingly, the rays of lightreflected from the mask window 224 are shown attenuated as backreflection is reduced by the AR coating.

FIG. 15E, for example schematically illustrates a planar window 224 onthe mask without an AR coating that is tilted or sloped such that thenormal (shown by dotted line) to the window is disposed at an angle, β,with respect to the central axis 267 of the optical axis from the exitpupil or ocular/eyepiece of the ophthalmic device to the window. Themask window receives a bundle of rays 265 of light (eithersimultaneously during flood illumination or more sequentially in a beamsteering approach) focused down by a focusing lens 270 at the output ofthe ophthalmic device. The maximum ray angle or cone angle of thefocused bundle of rays 265 is shown as α. In this example, |β|>α, whereα is the cone angle measured as a half angle as shown. In variousembodiments, |β|−Δ>α. As discussed above, Δ is the angle at which theprobe beam can be offset with respect to the probe optical path so asnot to be coupled back into the OCT instrument via retro-reflection andthereby disrupt the OCT signal by introducing noise. (See FIG. 15B.)Accordingly, rays in the bundle of rays 265 propagating along theoptical path from the ophthalmic instrument to the eye are not reflectedback toward the ophthalmic device at an angle within the collectionangle defined by the numerical aperture of the lens 270 such that thislight does not re-enter the ophthalmic device. Tilting or sloping thewindow 224 sufficiently beyond the angle of the steepest ray of lightfrom the probe beam can reduce retro-reflection. As discussed above, invarious embodiments, the magnitude of the tilt or slope angle β islarger than the cone angle α, where α is the cone angle measured as ahalf angle as shown and is a positive value, or the magnitude of thetilt or slope exceeds the angle of the ray 268 exiting the ophthalmicdevice (e.g., exiting the ocular lens 270 shown in FIG. 15E) that isincident onto the mask window at the largest angle providing greaterdeflection away from the optical axis 267 for that ray 268. Accordinglyin various embodiments, |β|>α thereby increasing the amount of rays thatare not retro-reflected back through the lens 270 and into theophthalmic device. As discussed above, in various embodiments, |β|exceeds a by at least Δ. The magnitude of the tilt or slope angle β ofthe optically transparent section 224 may thus be greater than the coneangle α established by the f-number or numerical aperture of theophthalmic device. In some embodiments, one or more of theserelationships are true for 50-60%, 60-70%, 70-80%, 80-90%, 90-95%,95-98%, 98-99%, or 99-100% of the light from the probe beam (e.g., asrays are swept through the range of angles to provide raster scanning).Combinations of these ranges are also possible.

In addition to being tilted or sloped, the optically transparentsections 224 may also be coated with an anti-reflective coating asdescribed above. In some embodiments, the respective portion of theoptically transparent sections 224 is tilted or sloping upward ordownward, as illustrated in FIGS. 14A-D. In other embodiments, therespective portion of the optically transparent sections 224 is tiltedor sloped temporally or nasally, or in a combination of upward/downwardand nasal/temporal directions.

FIGS. 16A-D illustrate a mask 300 for performing an eye exam accordingto an embodiment. The mask 300 is similar to the mask 200 shown in FIG.14, except that two of the one or more substantially opticallytransparent sections 224 a and 224 b are tilted or sloped temporally ornasally in opposite directions with respect to each other. In anembodiment, the two substantially optically transparent sections 224 aand 224 b are tilted or sloped symmetrically away from the nose andnasal lines or centerline. In other embodiments, combinations of tiltdirections are possible. For example, according to some embodiments, oneoptically transparent section 224 a is tilted or sloped upward ordownward, and the other optically transparent section 224 b is tilted orsloped nasally or temporally. In some embodiments, a portion of theoptically transparent sections 224 that intersect the incident lightbeam is planar, as illustrated in FIGS. 14 and 15. In other embodiments,a portion of the optically transparent sections 224 is curved, asdiscussed below.

FIGS. 17A-17C, for example, illustrate how curved windows 224 can beused as the optically transparent sections 224 of a mask and the effectof such curved windows on an incident probe beam 265. In certainembodiments, depending on the placement of the incident beam 265 withrespect to the mask window 224, the window may provide a perpendicularsurface for many of the rays of light in the beam thereby causingretro-reflection back into the channels of the ophthalmic instrumentthereby contributing to noise in the signal.

FIG. 17A, for example, shows a curved window 224 without an AR coatinghaving a center of curvature 272 that is located at the focus point 274of the optics 270 of the ophthalmic device. Such alignment can cause asignificant portion of the light to be retro-reflected back into theophthalmic device. The focus point 274 of the optics 270 in theophthalmic device may comprise the focal point of the lens or optics inthe ophthalmic system (e.g., in the ocular or eyepiece or left or rightoutput channel).

FIG. 17B shows a curved window 224 without AR coating having a center ofcurvature of the window that is behind or beyond the focus point of thelens 270. This positioning may be determined in part by the mask and theinterconnection between the mask and the ophthalmic device thatestablishes the spacing between the ophthalmic device and the eye of thesubject wearing the mask. In FIG. 17B, rays of light are retro-reflectedback toward the ophthalmic device at an angle within the collectionangle defined by the numerical aperture of the lens 270 such that thislight re-enters the ophthalmic device.

In contrast, FIG. 17C shows a curved window 224 without AR coatinghaving the center of curvature that is in front of the focal point 274of the optics. As discussed above, this positioning may be determined inpart by the mask and the interconnection between the mask and theophthalmic device that establishes the spacing between the ophthalmicdevice and the eye of the subject wearing the mask. Some of the rays onthe outer parts of the cone of rays 265, including the ray 268 directedat the largest angle are not retro-reflected back toward the ophthalmicdevice at an angle within the collection angle defined by the numericalaperture of the optics 270 such that this light does not re-enter theophthalmic device. However, rays closer to the optical axis 267 arecloser to being perpendicular with the normal of the window such thatthose rays are retro-reflected back toward the ophthalmic device at anangle within the collection angle defined by the numerical aperture ofthe optic 270 and thus re-enter the ophthalmic device. In variousembodiments where the ophthalmic device is a beam-scanning device suchas an OCT device or a scanning laser ophthalmoscope, a small offsetangle between the cone of rays 265 and the slope of the curved window224 is sufficient to sufficiently reduce or prevent retro-reflection oflight into the ophthalmic device.

FIGS. 17D and 17E schematically illustrate shifts of the center ofcurvature of the window to the left and the right. FIG. 17D shows acurved window 224 without AR coating having a center of curvature of thewindow that is to the left of the focus point and optical axis 267 ofthe lens 270. This positioning may be determined in part by the mask andthe interconnection between the mask and the ophthalmic device thatestablishes the spacing and positioning between the ophthalmic deviceand the mask as well as the eye of the subject wearing the mask. In FIG.17D, rays of light that intersect the curved window 224 to the right ofits center of curvature are retro-reflected at an angle that issubstantially directed away from the lens 270 and the optical axis 267.Light that intersects the window 224 to the left of its center ofcurvature is retro-reflected back toward the ophthalmic device at anangle within the collection angle defined by the numerical aperture ofthe lens 270 such that this light re-enters the ophthalmic device.

Similarly FIG. 17E shows a curved window 224 without AR coating having acenter of curvature of the window that is to the right of the focuspoint and optical axis 267 of the lens 270. As discussed above, thispositioning may be determined in part by the mask and theinterconnection between the mask and the ophthalmic device thatestablishes the spacing and positioning between the ophthalmic deviceand the mask as well as the eye of the subject wearing the mask. In FIG.17E, rays of light that intersect the curved window 224 to the left ofits center of curvature are retro-reflected at an angle that issubstantially directed away from the lens 270 and the optical axis 267.Light that intersects the window 224 to the right of its center ofcurvature is retro-reflected back toward the ophthalmic device at anangle within the collection angle defined by the numerical aperture ofthe lens 270 such that this light re-enters the ophthalmic device.

In these examples, the windows 224 are spherical. In other embodiments,however, the window 224 may have a curved surface other than spherical,e.g., aspheric surface curvature. In addition to being tilted or sloped,the curved optically transparent sections 224 may also be coated with ananti-reflective coating as described above.

FIGS. 18A-D illustrate a mask 300 for performing an eye exam similar tothe mask 200 shown in FIG. 14, except that two of the one or moresubstantially optically transparent sections 224 a and 224 b are curved.In particular, the substantially optically transparent sections 224 aand 224 b have outer surfaces as seen from the front of the mask havinga convex shape. These curved surfaces may be spherical in shape or maybe aspherical. For example, the curved surfaces may be an ellipsoidalsurface or an oblate spheroid surface, or have a shape characterized bya higher order polynomial or be combinations thereof. Other shapes arepossible. In various embodiments, the surface is more flat at the centerof the substantially optically transparent section and curves or slopesmore steeply away from the center of the substantially opticallytransparent section as shown by FIG. 18A-D. In some embodiments, themask has a size and the substantially optically transparent sections aredisposed such that the flatter central portions of the substantiallyoptically transparent section are along the line of sight of the wearer.Accordingly, in various embodiments, the surface is flatter closer tothe normal line of sight and slopes more steeply away from the normalline of sight.

Various embodiments of masks having optically transparent sections 224 aand 224 b that are curve and may be piano and have negligible opticalpower. Not having optical power will likely contribute to the comfortand viewing experience of the wear. Accordingly, optically transparentsections 224 a and 224 b may have anterior and posterior surfaces havingshapes that together provide that the optically transparent sections 224a and 224 b have substantially zero diopters of optical power. In someembodiments, however, the optically transparent sections 224 a and 224 bmay have optical power such as to accommodate individuals who needrefractive correction.

In some embodiments, the angle of incidence varies across transparentsection 224. A curved window 224 depending on the shape and/or positionwith respect to the focus of the probe beam may cause the angle ofincidence to vary across the transparent section 224.

FIG. 19 schematically illustrates a window 224 of a mask disposed infront of a pair of eyes such that most of the rays of light from theincident beam are reflected at angles beyond the collection angle withinthe numerical aperture of the optics 270 or exceeds than an offset angleΔ described above for beam-scanning devices. Accordingly, most of thelight does not re-enter the ophthalmic device. In particular, the window224 is sloped except for at the centerline where the nose of the weareris located. Additionally, the window has a slope that increases inmagnitude temporally. Moreover, the window is sloping such that all therays in the cone of rays 265 of the incident beam are directedtemporally upon reflection (unlike in the examples shown in FIGS.17A-C).

In the example shown in FIG. 19, the window 224 has a slope andcurvature that increases in magnitude temporally such that the slope orcurvature is maximum at the periphery or edges 273 of the window 224.This slope or curvature at the location of the line of sight (e.g.,within a range of interpupilliary distances between 50-80 mm or 25-40 mmfrom the centerline) is sufficiently high in magnitude to exceed theangle of the ray 268 exiting the ophthalmic device (e.g., exiting theocular lens 270) at the largest angle that is incident onto the maskwindow 224. Additionally, the slope or curvature of the window 224 issufficiently high in magnitude to deflect all or substantially all or atleast most of the other rays away from the optical axes 267 of theoutput channels of the ophthalmic device. At each point where rays fromthe probe beam intersect the window 224, the normal to the windowsurface is oriented with respect to the cone of rays 265 to deflect theray outwards or to retro-reflect the probe beam at an angle Δ describedpreviously for beam-scanning devices. Moreover, the rays are deflectedsufficiently so as not to be retro-reflected at an angle within thecollection angle defined by the numerical aperture of the output channelof the ophthalmic device such that this light is not coupled back intothe ophthalmic device so as to interfere with the signal (e.g., the OCTsignal).

Additionally, in various embodiments, the width of this curved window224 may be sufficient to account for the lateral position and movementof the oculars or output channels of the ophthalmic device. Increasingthe interpupillary distance of the pair of output channels of theophthalmic device effectively pushes the outermost ray 268 moretemporally. Accordingly, the width and curvature of the window 224 onthe mask can be established to ensure that half, or most, orsubstantially all, or all the rays of light from the left and rightoutput channels of the ophthalmic instrument are at a given instant intime or over the range of angles swept during a raster scan not incidenton the mask window at an angle where the rays are retro-reflected backat an angle within the collection angle defined by the numericalaperture of the channels such that the light is collected by thechannels and introduces noise to the signal. For example, if the angleof the ray 268 exiting the left and right channels of the ophthalmicdevice at the largest angle is 35 degrees (e.g., if the cone angle α is±35°), and the maximum lateral position of those rays is 40 mm from thecenterline 279 or nose line on the window of the mask, a shape can beconfigured for the window that ensures that none or substantially noneof the rays are incident on the transparent window in a perpendicularorientation and instead cause most, all, or substantially all theincident light to deflect outside the collection angle defined bynumerical aperture of the left and right channels of the ophthalmicdevices.

As discussed above, the substantially optically transparent sections 224a and 224 b have outer surfaces as seen from the front of the maskhaving a convex shape and are aspherical. For example, the curvedsurfaces may be ellipsoidal, toroidal, or have a shape characterized bya higher order polynomial or combinations thereof.

Additionally, in various embodiments the optically transparent sections224 a and 224 b are plano and have negligible optical power. Theoptically transparent sections 224 a and 224 b may have anterior andposterior surfaces having shapes that together provide that theoptically transparent sections 224 a and 224 b has substantially zerodiopters of optical power. In some embodiments, however, the opticallytransparent sections 224 a and 224 b may have optical power toaccommodate individuals who need refractive correction.

Moreover, the transparent section 224 can be comprised of a curvedtransparent outer surface sufficiently sloped such that the angle ofincidence of the rays of light output by an accompanying OCT machinewhen interfaced with the mask is not normal to the transparent section224 at most or substantially all the points of incidence on transparentsection 224 and the slope or tilt is configured to deflect the rays awayfrom the optical axis and outside the collection angle of the OCTmachine (e.g. |β|>α). In some embodiments, such as beam-steering opticaldevices, the difference between angle |β| and angle α is be greater thanan angle Δ such that |β|−Δ≥α to prevent any retro-reflected beam fromimpinging on the beam-steering device, such as a galvanometric mirror orMEMS mirror, and being sensed by the device. In some embodiments, thisrelationship is true for 50-60%, 60-70%, 70-80%, 80-90%, 90-95%, 95-98%,98-99%, or 99-100% of the light from the probe beam as used (e.g., floodillumination or swept) to generate images by the ophthalmic device orcombinations of these ranges.

Accordingly, in various embodiments, only 3-5% or 2-4%, or 1-3% or0.5-1% or 0.1-0.5% or 0.05-0.1% or 0.01-0.05% of the light is reflectedback into the ophthalmic device.

FIGS. 20A-D schematically illustrate a mask 300 for performing an eyeexam having transparent sections 224 with curvatures such as shown inFIG. 19. Accordingly, the optically transparent sections 224, sometimesreferred to herein as an optically transparent region, mask window orcurved transparent section, have wrap and sweep back progressively withdistance from a centerline of the mask (nasal line) 273 where the noseof the wearer would be positioned. Additionally, the mask window alsohas curvature in the superior-inferior meridian. Accordingly, this maskmay reduce retro-reflection of light from the optical coherencetomography instrument back into the instrument.

In some embodiments, the curved transparent section 224 extends acrossall of distal portion 218. In some embodiments, curved transparentsection 224 is only a portion of distal portion 218 (e.g., see FIGS.21A-21D in which the optically transparent section does not extend to oris displaced from the lateral edges of the mask). As shown, the mask hasa front sheet that sweeps backward (e.g., posterior) and outward (e.g.,lateral) from the centerline 279 and provides suitable curvature toreduce reflection back into the OCT instrument and thereby reduce noiseon the OCT signal.

In certain embodiments for example, the mask includes left and rightsubstantially optically transparent sections 224 a, 224 b disposed onleft and right sides of the centerline 273. The left and rightsubstantially optically transparent sections 224 a, 224 b may bedisposed with respect to each other to accommodate interpupillarydistances (see FIG. 19) between about 50-80 mm, for example, for adults.Accordingly, the distance between the normal line of sight and thecenterline (which can be centered on the nose of the patent) is about25-40 mm. In some embodiments, at least the right substantiallyoptically transparent section 224 a (or the left section 224 b or both)has at least a portion thereof that is sloped such that at a location onthe right substantially optically transparent section 224 a (leftsection 224 b or both) that is 30 mm from the centerline (e.g., lateralof the superior inferior meridian), the right substantially opticallytransparent sections is sloped by at least 10° or more, at least 20° ormore, at least 30° or more, at least 40° or more, at least 50° or moreup to 70° or 80° or 90°, with respect to a line through that locationthat is parallel to the centerline. This angle may be established by thecone angle α discussed above and can have a magnitude greater than 10°such as more than 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, upto 70° or 80° or 90° etc. The right substantially optically transparentsection (or left section or both) may have the same slope magnitude orbe increasingly sloped (for example, have a magnitude greater than forexample 10° 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°) atlocations progressively more temporal from the location (e.g., greaterthan 30 mm in distance from the centerline) at least to about 35 mm or40 mm etc. from said centerline. In some embodiment, the location can be20 mm, 22.5 mm, 25, mm, 27 mm, 29 mm, 31 mm, 33 mm, 35 mm, 37 mm, 39 mm,or any range therebetween. In some embodiments, at 25 mm from thecenterline, the magnitude of the slope may be greater than for example10° 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60° and/or the slopemay exceed the cone angle such that the outermost ray of light from theocular in the ophthalmic instrument is deflected away from the opticalaxis of the ocular. Likewise, for locations progressively more temporal,the optically transparent section may be sloped (for example, may have aslope with magnitude greater than for example 10° 15°, 20°, 25°, 30°,35°, 40°, 45°, 50°, 55°, 60°), may have constant slope, or varyingslope, e.g., increasingly sloped. Additionally, in some embodiments, theright (left or both) substantially optically transparent section(s) issloped by at least 15°, 17°, 19°, 21°, 23°, 25°, 27°, 29°, 31°, 33°,35°, 37°, 39°, 41°, 43°, 45°, 47°, 49°, 51°, 53° or 55°, in magnitude atsaid location or ranges therebetween. Accordingly, in some embodimentsthe substantially optically transparent section sweeps back asillustrated in FIG. 19.

Likewise, the window exhibits wrap. In some embodiments, the windowwraps at least partially around the side of the face or at least beginsto wrap around the side of the face. This curvature is desirable wherethe rays of light from the ophthalmic instrument might intersect theoptically transparent window. Since different subjects will havedifferent interpupilary distances, and the ophthalmic instrument may beadjusted accordingly to direct the probe beam through the pupil of theeye, the rays from the probe beam may be incident over a range oflocations on the substantially optically transparent sections. A windowthat exhibits wrap over a region thereof may thus be desirable to reduceretro-reflection back into the instrument. In various embodiments,windows that sweep rearward with distance progressively more temporal ofthe centerline 273 of the mask 300 are useful in deflecting lighttemporally and outside the collection angle of the ophthalmic device.The slopes may be substantially constant in the temporal region or maybe varying.

Although FIG. 19 is a useful reference for the discussion above wherecurvature is shown along a nasal-temporal meridian, in considering thesuperior-inferior meridian, reference to FIGS. 17A-E may be beneficial.In various embodiments, the window is curved along the superior-inferiormeridian. This curvature as well as the distance of mask from the ocularon the ophthalmic instrument (as established by the mechanical interfacebetween the mask and the ophthalmic device) may be such that a pluralityof, many, possibly most, or substantially all rays in the bundle of raysfrom the ocular are deflected upward or downward and outside thecollection angle of the ocular.

In various embodiments, combinations of tilt directions and curvature oftransparent sections are possible. FIGS. 21-27 and 29A-29C showadditional designs having differently shaped windows. FIGS. 21A-D aswell FIGS. 26 and 27 schematically illustrate a design having a planarportion 291 of the substantially transparent section that is locatedmore nasally and an adjacent planar sloping portions 293 locatedtemporally. A transition 295 between these portions 291, 293 is curved.In certain embodiments, this transition 295 has a curvature of acircular arc having a center and radius of curvature. The slopingportions may slope along a nasal-temporal direction, for example, by atleast as much as the right and left substantially optically transparentsections 224 a, 224 b described above. Curvature or slope in thesuperior-inferior direction is negligible. FIGS. 29A-29C illustrateanother mask 300 with a substantially transparent section 224 having aprofile similar to that shown in FIGS. 21A-21D except that the lateraledges of the substantially transparent section 224 extend to the lateraledges of the cushion 305. Additional discussion regarding this design isprovided below in connection with FIGS. 28A-D.

FIGS. 22-24 and 25A-D (as well as 39A-D and 40A-D) show transparentsections that are curved in both nasal-temporal meridian andsuperior-inferior meridian. (FIGS. 22 and 23 show the same compoundcurved surface as in FIG. 24.) In various embodiments such as shown inFIG. 25B, the curvature or slope of the substantially transparentsection 301 in the nasal-temporal direction is negligible closer to thecenterline until reaching a temporal location where the magnitude of theslope increases temporally to generate a curved temporal section thatsweeps backward. The slope can, for example, be at least as much as theright and left optically transparent sections 224 a, 224 b describedabove. The curvature or the magnitude of the slope of the substantiallytransparent section 301 along the superior-inferior meridian starts outhigh in magnitude at the inferior location, reduces in magnitude to anegligible amount halfway between the inferior and superior extent ofthe convex shaped substantially transparent section 301 and increasesagain at the superior locations. The curvature is such that themagnitude of slope increases with increasing distance superiorly andinferiorly beyond the central flat non-sloping region. The curvatures donot slope or the slope is substantially negligible along the nasaltemporal meridian in this central flat non-sloping region as well. Invarious embodiments this central flat non-sloping region can be ⅛, ⅙, ¼,⅓ or ½ to ¾ or values in any range formed by any of these values theextent of the convex shaped substantially transparent section along thenasal temporal meridian, the superior inferior meridian, or both. Inother embodiments, the curvature of the substantially transparentsection 301 is equal in both the nasal-temporal meridian and thesuperior-inferior meridian at any given point on the surface of thetransparent section 301 such as with a spherical surface. In some cases,enhanced or maximum deflection of the back reflected OCT beam isobtained when the curvatures in the two meridians are equal such as fora spherical surface where the radius of curvature in one meridian isequal to the radius of curvature in the perpendicular meridian. Aspherical surface has the same amount of drop with distance laterally aswith movement in position inferiorly or superiorly. In contrast, invarious other embodiments, such as for an ellipsoid or paraboloidsurface, the curvature in the two meridians is different. For anellipsoidal, toroidal or paraboloid surface, the curvature is steeper inone meridian than another. When the curvature is the same in orthogonalmeridians, however, such as with a spherical surface, the amount oflight that is deflected away from being scattered back into the OCTmachine can be increased or maximized while distortion (e.g., pincushion distortion or astigmatism) is reduced or minimal. In variousconfigurations, the outer surface and the inner surface are curved andhave the same curvature but different centers of curvature. In certainconfigurations, the curvature of both the outer surface and the innersurface are defined by the same center of curvature, e.g., thecurvatures have different radii of curvature and the same center ofcurvature. Accordingly, as discussed above, in certain configurationsthe thickness remains substantially constant across the transparentwindow or large portions thereof that provide access of the OCT beam tothe user's eye. Such constant thickness can reduce aberrations such as,for example, astigmatism. In other configurations, the thickness variesacross the transparent window or large portions thereof that provideaccess of the OCT beam to the user's eye. Such varying thickness canincrease stiffness and rigidity.

In various embodiments, one or more of the optically transparent regionscan be piano and not have optical power. In some embodiments, howeverone or more of optically transparent section can have optical power atleast in one meridian. In certain embodiments wherein the front and rearsurface of the optically transparent section have offset centers thatprovide astigmatism, the optically transparent section has optical powerin at least one of the meridians.

FIGS. 28A-D illustrate some of the design considerations entailed invarious embodiments of the mask window. For certain ophthalmicinstruments, different modes of operation may involve use of probe beamswith different characteristics.

FIG. 28A for example, illustrates a mode of operation where an OCTinstrument is configured to output a planar non-focused wavefront.Optics in the OCT instrument are configured to be telecentric. FIG. 28Atherefore shows on a plot of angle of incidence (in degree) versusdistance (in mm) from the centerline, the output from the ocular oreyepieces for the left and right channels of the ophthalmic device(e.g., OCT instrument). The plot shows an angle of 0° for each of therays across the aperture of the ocular for both the left and rightchannels.

FIG. 28B illustrates a mode of operation where an OCT instrument isconfigured to output beam that sweeps across a range of angles α asdiscussed above. A plot of angle of incidence (in degree) versusdistance (in mm) from the centerline shows the output of the ocular oreyepieces for the left and right channels of the ophthalmic device(e.g., OCT instrument). These plots show the change in angle for thedifferent rays across the aperture of the ocular for both the left andright channels.

The OCT instrument is configured to provide modes of operation usingprobe beams characterized by the plots shown in FIGS. 28A and 28B.Accordingly, in various embodiments, a mask that can reduceretro-reflection back into the OCT system for both of these modes isbeneficial. The signal-to-noise ratio can thereby be increased bycurtailing introduction of noise into the signal by retro-reflection offthe mask. Accordingly, FIG. 28C shows the combination of angles ofincidence in the probe beam for the two modes on a single plot.

FIG. 28D presents a solution for reducing retro-reflection. As discussedabove, rays perpendicularly incident on the mask will be retro-reflectedback into the OCT instrument and introduce noise to the OCT signal.However, by adding a slight offset Δ to the reflected beam such that thebeam is not incident perpendicular on the mask and does not reflectdirectly back in the same direction the amount of rays that return backinto the OCT instrument can be reduced. The plot in FIG. 28D shows theaddition of this offset. In particular, an offset of 1° has beenprovided.

In this example, the inter-optical distance, the distance between thecenters or optical axes of the oculars or eyepieces, which is related tothe interpupillary distance of the subject, was 54 mm. Accordingly, aline of sight for wearers would be expected to be at 27° in bothdirections from the centerline for each of the left and right eyes. Themagnitude of the slope of the mask is therefore set to increasecontinuously in the regions between 27 mm and about 38 mm where themagnitude of the slope reaches a maximum (just beyond the angle of theoutermost ray in the bundle shown in FIGS. 28A and 28B). This curvatureis to address the mode of operation represented by FIG. 28B. The small1° in the region between 0 mm and 27 mm is to address the mode ofoperation represented by FIG. 28A where the rays are each at an angle ofincidence of 0° without the offset. FIG. 28D shows a cross-section ofthe mask. The cross-section shows a wide central region 291 between forthe right eye between 0 and 27 mm without a large amount of slope, atransition region 295 between 27 mm and 38 mm where the magnitude of theslope is increasing, and a region 293 from 38 to 49 mm where the slopemagnitude remains constant. A similar shape could be used for the lefteye thereby providing a symmetrical configuration.

Other variations are possible. For example, in one embodiment, for theright eye, the magnitude of the slope at 27 mm could be set to be solarge as to account for α+Δ, namely, β≥α Δ at 27 mm. The transitionregion 295 could thus start around 13 or 14 mm and be complete by 27 mmwhere the magnitude of the slope could remain constant for distancesbeyond 27 mm (e.g., in region 293). In the region 291 between 0 to 13 or14 mm, the small slope offset of 1° or so could be introduced. A similarshape could be used for the left eye thereby providing a symmetricalconfiguration.

The various shaped windows may further include an AR coating asdiscussed above.

As illustrated in FIGS. 15B, 26, and 27, rays of light corresponding tothe probe beam may be swept. For example, the probe beam (for OCT orSLO) may comprise a beam having a small beam width (e.g., 5 to 10 timesor more smaller than the exit pupil of the ocular) that is swept acrossthe focusing lens and/or exit pupil in the ocular of the ophthalmicdevice. Accordingly, only portions of the rays in the bundle of raysdescribed above will be present at a given time. Nevertheless, invarious embodiments, the beam sweeps through the different angles withinthe cone of angles, α, referred to above. Accordingly, as discussedabove, the shape of the mask window can be configured to be sufficientlysloped such that these rays, and in particular, this small beam, is notretro-reflected back into the instrument to introduce noise into thesignal as the beam is swept through the range of angles defined by thecone angle, α.

In some embodiments, similar to the mask 100 illustrated in FIG. 1, theproximal portion 254 of the mask 200 is inflatable or deflatable, andthe rear surface 222 is configured to conform to contours of thepatient's face and align the one or more substantially opticallytransparent sections 224 of the distal portion 218 with the patient'seyes when the proximal portion 254 is inflated or deflated. In someembodiments, the mask 200 includes an inflation port (not shown)providing access to inflate or deflate the proximal portion 254. In someembodiments, the proximal portion 254 has two cavities 260 a and 260 bextending from the rear surface 222 toward the distal portion 218. Thetwo cavities 260 a and 260 b are aligned with the one or moresubstantially optically transparent sections 224 and defining twoopenings on the rear surface 222 to be aligned with the patient's eyes.The rear surface 222 is configured to seal against the patient's face soas to inhibit flow of fluid into and out of the two cavities 260 a and260 b through the rear surface 222. In some embodiments, the mask 200includes an ocular port (not shown) providing access to at least one ofthe two cavities for gas or fluid flow into the at least one of the twocavities 260 a and 260 b.

Removable Masks

In some scenarios, it may be desirable to provide an ophthalmic device(e.g., an optical coherence tomography device or other ophthalmicdiagnostic instrument) with a small interpupillary distance toaccommodate many users. In some scenarios, it may be desirable to allowthe patient's eyes to be positioned as close to the optical coherencetomography device as possible to increase the field of view for thepatient, the device or both the patient and device. In theseembodiments, a mask can prolong the life of the optical coherencetomography device by providing an optically transparent barrier betweenthe patient and the device. Without the mask, build-up of contaminantsand other environmental factors can damage the optical coherencetomography device or the patient could be injured by moving objectswithin the OCT device. Additionally, germs may be transferred from oneuser to another user. Although the embodiments described below aredescribed in relation to an optical coherence tomography device, thehygienic barriers can be used with any ophthalmic system.

The mask can be attached to the optical coherence tomography devicebefore each use and removed after each use such that the mask can bedisposed of after a single use or a few uses (e.g., 2, 3, 4, 5, 6, orotherwise). In various implementations, the subject inserts the mask1032 into the contoured portion 1004 of the OCT device 1000 and thenbring his/her head into contact with the mask 1032. In variousimplementations, the user could bring his/her head into contact with themask 1032, and then insert the mask 1032 into the contoured portion 1004of the OCT device 1000. Likewise, the subject may remove his/her headfrom the mask 1032 and then remove the mask 1032 from the contouredportion 1004 when the examination is complete or remove both his/herhead and the mask 1032 from the contoured portion 1004, and then removethe mask 1032 from the user's head. Disposable masks provide a hygienicbarrier between the user and the optical coherence tomography device.Further, unlike reusable masks, disposable masks prevent the build-up ofdust or other contaminants on the mask, so the mask can be used withsubstantial or maximum clarity. The mask 1032, whether disposable ornot, would likely reduce contaminant build up on the OCT device 1000.The mask also prevents contaminants from entering the optical coherencetomography device and prevents user appendages, such as fingers, frombeing inserted into the machine where they could be damaged by movingparts.

The hygienic barrier can take the form of a mask as described herein.The hygienic barrier (referred to herein as a “mask” or “goggle”) can beattached to and removed from an ophthalmic instrument (e.g., a binocularoptical coherence tomography device) such that an incident light beamfrom the ophthalmic instrument is transmitted to an eye of a user. For abinocular optical coherence tomography device, the hygienic barrierpermits incident light beam(s) from the ophthalmic instrument to betransmitted to both eyes of a user.

FIG. 52 schematically illustrates the hygienic barrier 1500. In general,the hygienic barrier 1500 can include a first optically transmissivesection (e.g., optically transparent). The first optically transmissivesection can be optically interfaced with the ophthalmic instrument suchthat, during use, an incident light beam 1520 from the ophthalmicinstrument 1510 can be transmitted through the first opticallytransmissive sections to an eye 1530 of a user. The first opticallytransmissive section has a light transmission region 1540 through whichthe incident light beam 1520 is transmitted. Areas of the firstoptically transmissive section through which the incident light beam isnot to be transmitted, if present, do not form a part of the lighttransmission region 1540. In some implementations, the first opticallytransmissive section can form the entirety of the hygienic barrier. Insome implementations, one or more edges of the first opticallytransmissive section may be surrounded by a non-transmissive section.Although FIG. 52 schematically illustrates the mask 1500 having a singlecurvature, the mask 1500 may have multiple curvatures. For example, asshown in FIG. 48B, the mask may have a first radius of curvaturecentered directly behind the nose bridge region and second and thirdradii of curvature configured to be centered directly behind therespective light transmission regions. The second and third radii ofcurvature may be the same or different from the first radius ofcurvature. The second curvature may be the same as the third radius ofcurvature, or may be different.

In some implementations, the hygienic barrier has a second opticallytransmissive section. The second optically transmissive section has alight transmission region through which an incident light beam istransmitted to the other eye of the user. Reference to characteristicsof the optically transmissive section or first optically transmissivesection can also be applied to the second optically transmissivesection.

The optical characteristics of the hygienic barrier can help reduce orminimize back-reflections into the detector of the optical coherencetomography device as described above. The optically transmissivesection(s) of the hygienic barrier may comprise a material having ashore D hardness of at least 75, at least 80, at least 85, or more. Theoptically transmissive sections may comprise polycarbonate or PMMA. Thedesired optical characteristics may also be achieved based on the shapeof the hygienic barrier. For example, for some designs, a thickness atany location of the light transmission region can be no greater thanabout 3.0 mm, no greater than about 2.5 mm, no greater than about 2.0mm, no greater than about 1.5 mm, no greater than about 1.0 mm, nogreater than about 0.75 mm, no greater than about 0.5 mm, no greaterthan about 0.25 mm, or any ranges between any of these values. Thethickness of the entire light transmission region can be substantiallyuniform (e.g., a thickness at any location of the light transmissionregion can be within about 0.5% of an average thickness of the lighttransmission region). A radius of curvature of the light transmissionregion can be between about 40 mm and about 60 mm, between about 45 mmand about 65 mm, between about between about 50 mm and about 70 mm, orany sub-ranges within these ranges. A length or diameter of the lighttransmission region can be at least about 15 mm and/or less than orequal to about 40 mm, such as between about 20 mm and about 30 mm,between about 30 mm and about 40 mm, or other ranges between thesevalues.

Since any of the masks or goggles herein can be designed to be removablyattached to an ophthalmic instrument, certain masks or goggles may notinclude features for adhering, attaching, or strongly adhering orattaching to a user's head or face (e.g., straps, armatures, over theear supports, and/or over the nose supports). For certain masks, themask is supported by or rests on the ophthalmic instrument, not theuser's head or face. Likewise in some cases, if the user's head or faceis tilted 15 degrees from a longitudinal axis L of the user (see FIG. 3)when standing, the mask would fall off the user's head or face. Anyforce holding the mask to the head or face of the user is not sufficientto overcome the force of gravity. To the extent that the mask has anyarmatures (e.g., see FIGS. 44A-44D), these armatures may facilitatealignment and not secure the mask to the user's head or face despitegravitational force when the head is in the tilted position. Asdiscussed further below, the mask in FIGS. 44A-44D is still supported byand rests on the ophthalmic instrument.

In some configurations, a lateral side or armature of the mask extendsno more than 3.0 inches (or no more than about 2.0 inches or no morethan 2.0 inches, or no more than 1.5 inches, or no more than 1.0 inches,or any ranges between any of these values) from the anterior surface ofthe mask, such that the posterior end of the mask is anterior of theuser's ear. Since the mask is not supported by the user's face, in someimplementations, there may be no cushions in the forehead and/or noseregions of the mask.

Described below are different features for attaching the masks to theoptical coherence tomography device in a stable manner, but so the maskcan be easily removed. Features are also provided to prevent or reducemovement of the user's head to improve visualization of the internaldisplays and improve OCT measurements. Additional components may bepresent, such as a disposable nose and/or forehead shield.

FIG. 30A illustrates a binocular optical coherence tomography device1000 (also referred to herein as OCT device or OCT machine) having acontoured receptacle 1004 configured to adapt the OCT device 1000 toreceive the mask 1032. The contoured receptacle 1004 can be integrallyformed with or permanently secured to the OCT device 1000. However, asdescribed further below, the contoured receptacle 1004 can be a separatecomponent removably secured to the OCT device 1000. In either case, thecontoured portion 1004 can be constructed from a metal, plastic, orother material.

The contoured receptacle 1004 can provide a non-planar contouredreceptacle interface 1008 (e.g., generally concave) to receive the mask1032. As shown in FIG. 30A, the contoured receptacle 1004 can includespaced apart apertures 1016 that provide a conduit between the eyes ofthe user and optics of the OCT device 1000. The apertures 1016 can bespaced apart by a bridge 1020 to receive a bridge 1044 of the mask 1032(see FIG. 31). As described in further detail below, the contouredreceptacle 1004 can include attachment features such as attachmentportions 1024 on lateral sides of the contoured receptacle 1004 forremovably securing and stabilizing the mask 1032. Attachment featurescan be positioned at any number of locations, such as around a peripheryof the contoured receptacle 1004 to secure the mask 1032. For example,the contoured receptacle 1004 can include a number of retention members1022 around the periphery of the contoured receptacle 1004 to constrainmask 1032 movement in one or more directions. The retention members 1022can be surface features (e.g., projections, ridges, pins, indentation,opening, etc.) that restrain movement of the mask 1032 or engagecorresponding features of the mask 1032 (e.g., a groove, ridge,indentation, or opening and a corresponding projection, ridge,extension, etc.). As shown in FIG. 30A, the contoured receptacle 1004can include a retention member 1022 along an upper region of the bridge1020 to restrain upward movement of the mask 1032. The contouredreceptacle 1004 may include additional retention members 1022 along anupper or lower edge of the contoured receptacle. The attachment betweenthe mask 1032 and the contoured receptacle 1004 constrains the mask 1032from movement in at least one, possibly, two, three, or more degrees offreedom. Overall, the mask may be constrained in six degrees of freedom(x, y, z, and three degrees of rotation) yet allows easy attachment andremoval of the mask 1032. The mask being so constrained, the maskconstrains the subject's head.

Upward of the contoured receptacle 1004, the OCT device 1000 can includea forehead region 1002 against which the user's head rests. Downward ofthe contoured receptacle 1004, the OCT device 1000 can include a noserecess 1012 for receiving the user's nose. A microphone can bepositioned in or around the nose recess 1012 for voice recognitionpurposes (e.g., for activating the OCT device, commanding the OCTdevice, providing input or feedback to OCT instruments, etc.). Althoughnot shown, when the mask 1032 is engaged with the contoured receptacle1004, the mask 1032 may extend upward or downward of the contouredreceptacle 1004 to provide a larger hygienic surface. A forehead shieldand/or a nose shield of the mask 1032 may be rigid or flexible to adjustto the contours of the user's face. In other embodiments, the foreheadshield 1001 and/or the nose shield 1003 may be separate disposablecomponents that may be attached to the OCT device 1000 before or afterthe attachment of the mask 1032 (see FIG. 30C). For example, theforehead shield 1001 and the nose shield 1003 can be thin pieces (e.g.,made of plastic) removably adhered to the OCT device 1000. A stack ofsuch forehead shields 1001 and/or nose shields 1003 may be adhered tothe OCT device 1000. A single forehead shield 1001 and/or a single noseshield 1003 may be removed after a subject completes an examination. Theforehead shield 1001 and the nose shield 1003 can be applied prior tothe attaching the mask 1032. However, in other implementations, theforehead shield 1001 and the nose shield 1003 may be applied afterattaching the mask 1032.

In some scenarios, it may be desirable for the OCT device 1000 toinclude an interlock switch 1076 (see FIG. 30A) or switches or sensors,such as electrical contact, optical, resistance-based switches, or othersensor, to indicate engagement of the mask 1032 with the OCT device1000. The interlock switch 1076 can be positioned along the interface1008 or on the lateral surfaces 1024 used to secure the mask 1032 to thecontoured receptacle 1004. These switches 1076 can be configured to stopmovement of internal components or operation of the OCT device 1000 ifthe mask 1032 is not inserted during device or exam startup or if themask is removed during operation of the optical coherence tomographydevice.

As shown in FIG. 30A, the OCT device 1000 can include shutter(s) 1028,for example, distal of the contoured receptacle 1004 or within theapertures 1016 of the contoured receptacle 1004. FIG. 30A illustratesthe shutter(s) 1028 in a closed position (see FIG. 30A) when the mask1032 is detached or incorrectly attached to the contoured receptacle1004. As shown in FIG. 30B, the shutters 1028 can be configured totransition to an open position (see FIG. 30A) when the mask 1032 iscorrectly attached to the contoured receptacle 1004.

As shown in FIG. 31, the mask 1032 can include optically transparentsections or portions 1040 (e.g., optically transparent to lightwavelengths between 400 nm and 1550 nm or to visible light waves or oneor more portions of these wavelength regions). In certain embodiments,the instrument uses wavelength at or around 450, 520, 635, 780, 830 and1000-1120 nm. Therefore, the mask or goggles and in particular one ormore optically transparent section may, in some implementations,transmit more than an octave of light wavelengths. In some embodiments,the optically transparent portions 1040 are optically transparent tolight wavelengths between 450-650 nm, 750-850 nm, 980-1120 nm, or anycombination thereof. The optically transparent sections 1040 may betransparent to one or more portions of these ranges or of the visibleand/or near IR spectrums in some embodiments.

In some embodiments, the thickness of the mask 1040 is the same from thecenter to the edge to reduce optical distortion. Such constant thicknessembodiments may, for example, have inner and outer or front and rearsurfaces of the distal sheet member that are spherical curvatures havingthe same center of curvature. This center of curvature may, in differentexamples, be disposed in the central meridian through the nose andlikewise through the center of eyewear. In certain cases, where the maskincludes separate left and right substantially optically transparentsections for the left and right eye's respectively, each transparentsection may have a corresponding center of curvature that coincides withthe center of curvature for both the front and rear surface of the ofsubstantially optically transparent section. In some cases, the centersof curvature to coincide with the centers of the eye or pupil of anaverage person. For instance, the centers of curvature for the left andright eyes might be separated by 60 mm or 65 mm or a distancetherebetween. In certain implementations, the centers of curvature areseparated by 34 mm so the centers of curvature are neither on themeridian nor on the pupillary axis. A constant thickness can reduceaberration (e.g. distortion). In some embodiments, the thickness of themask 100 is the same (e.g., from center toward the edge or for the leftsubstantially optically transparent section or for the rightsubstantially optically transparent section) over an area of about 2cm², 3 cm², 4 cm², 5 cm², 6 cm², 7 cm², 8 cm², or ranges between any ofthese values. The area may be larger or smaller as well in differentimplementations. This thickness may be, for example, about 0.5 mm thickor other values. Other thicknesses could include 0.1 mm, 1.0 mm, 1.5 mm,2.0 mm, or 2.5 mm. In various embodiments, the thickness might besufficient to be impact resistant. In various embodiments, therefore,the impact resistance for the mask complies with the ANSI standard ANSIZ87. In one example, the outer radius is 54 mm, the inner radius is53.5, and the thickness is 0.5 mm. The center of curvature is the sameand the surfaces are spherical. In another example, the window may bethinner in the middle and thicker at the edge. The inner (back) radiuscan be smaller than the outer (front) radius, but the center ofcurvature for the inner radius is shifted forward to create a thinportion at the center (e.g., 12 o'clock position in the cross-section inthe nasal-temporal meridian) and relatively thicker portions toward theedges.

The optically transmissive portions or sections 1040 can be separated bya mask bridge 1044 that is received by the bridge 1020 of the contouredreceptacle 1004. When the mask 1032 is correctly attached to thecontoured receptacle 1004, the optically transmissive portions 1040 canalign with the apertures 1016 of the contoured receptacle 1004. In thismanner, light from a light source in the OCT machine can be directedonto the subject's eyes and light reflected or scattered from thesubject's eye can be directed to optics in the OCT device 1000. The mask1032 can include a proximal surface 1048 and a distal surface 1052 (seeFIG. 32A). The proximal surface 1048 can provide an interface betweenthe mask 1032 and the user (e.g., user's head, face, etc.), while thedistal surface 1052 can provide an interface between the mask 1032 andthe contoured receptacle 1004.

As shown in FIGS. 32A-32C, the mask 1032 can include armatures 1034 oneach lateral side of the mask 1032. A distal portion of the armature1034 can include an attachment portion 1036 configured to interface withthe attachment portions 1024 of the contoured receptacle 1004.Appendages 1056 may extend proximally from the attachment portions 1036to provide a lateral interface between the mask 1032 and the user (e.g.,sides of user's face and/or head) and limit or prevent lateral movementof the user's head when the mask is secured to the OCT device 1000. Theappendages 1056 may be cushioned to provide comfort and/or resilient toconform to a width of the user's head. In one example, the appendages1056 may be curved (e.g., curved radially inward of the attachmentportions 1036).

FIGS. 32A-32C illustrate the steps of attaching the mask 1032 to thecontoured receptacle 1004. In FIG. 32A, the armatures 1034 arepositioned in an initial configuration. The armatures 1034 can flex sothe attachment portions 1036 of the contoured receptacle 1004 can beinserted into attachment portions 1024 of the contoured receptacle 1004(see FIG. 32B). For example, the armatures 1034 can be springs biased tothe initial configuration. The armatures 1034 can be, for example,plastic springs (e.g., including PMMA) or metal springs. The attachmentportion 1024 of the contoured receptacle 1004 can include a recess 1026configured to receive a protrusion 1038 of the attachment portion 1036of the mask 1032 (or other combination of features to form a snap-fit orother interlocking joint). Although, in other configurations, theattachment portion 1024 of the contoured receptacle 1004 can include aprotrusion to be received by a recess of the attachment portion 1036 ofthe mask 1032. In some embodiments, the attachment portions 1036 canreturn to the initial configuration when the attachment portions 1036 ofthe mask 1032 engages the attachment portions 1024 of the contouredreceptacle 1004 (see FIG. 32C).

In other configurations, the attachment portions 1024 of the contouredreceptacle 1004 can flex instead of or in addition to flexure of theflexible armatures 1034 described above. For example, as shown in FIGS.33A-33C, the attachment portions 1024 can flex outward to accommodatethe attachment portions 1036 of the mask 1032. Similar to the armatures1034, the attachment portions 1024 can be springs biased to an initialconfiguration. The attachment portions 1024 can be, for example, plasticsprings (e.g., including PMMA) or metal springs.

Other attachment features than those described above are imaginable. Forexample, the attachment portions 1024 of the contoured receptacle 1004and the attachment portions 1036 of the mask 1032 can form a ball detentconnection. As shown in FIGS. 34A-34C, the attachment portion 1024 ofthe contoured receptacle 1004 can include a number of ball features 1060(e.g., one, two, or more), while the attachment portion 1036 of the mask1032 can include a number of corresponding openings 1064. Although, inother configurations, the attachment portion 1036 of the mask 1032 caninclude the ball features and the attachment portion 1024 of thecontoured receptacle 1036 can include the openings. Other arrangementsare possible. Similar to the embodiments described above, the armatures1034 and/or the attachment portions 1024 of the contoured receptacle1004 may flex.

Notably, in various embodiments such as those described above andelsewhere herein while the mask is worn, the armatures 1034 apply inwardpressure keeping the subject's movement at least somewhat constrainedwhen the mask 1032 is attached to the OCT device 1000. Additionally,while the mask 1032 is worn and the mask 1032 is attached to thecontoured receptacle 1004, the outward pressure applied by the subject'shead on the armatures 1034 promotes secure engagement with the OCTdevice 1000 by pressuring the armatures 1034 against the contouredreceptacle 1004 (e.g., attachment portions 1024).

In yet another configuration, the mask 1032 can be removably connectedto the contoured receptacle 1004 using fasteners (e.g., screws, posts,adhesives, or otherwise). As shown in FIG. 35A, the mask 1032 caninclude a lateral extension 1068 extending from each armature 1034. Thefastener 1072 can join the lateral extension 1068 to the contouredportion 1004.

As shown in FIGS. 36A and 36B, the appendages 1056 can flex toaccommodate the user's head after the attachment portion 1036 of themask 1032 engages the attachment portion 1024 of the contoured portion1004. FIG. 36A illustrates the appendages 1056 in an initialconfiguration. As the user's head moves toward the mask 1034, theappendages 1056 can flex outward to accommodate the user's head (seeFIG. 36B). A distal portion of the appendages 1056 or a junction betweenthe appendages 1056 and the attachment portion 1036 of the mask 1032 canflex against the attachment portions 1024 of the contoured receptacle1004. When the user is properly wearing the mask 1032, an inner surface1058 of the appendage 1056 can contact the user's head to constrainlateral movement of the user's head. The inner surface 1058 may becushioned (e.g., with foam, gel, or other conformable material) toincrease comfort. As described above, the armatures 1034 can be springsbiased to the initial configuration, such that when the user's head isremoved, the armatures 1034 can return to the initial configuration. Incertain embodiments, the mask armatures 1034 and appendages 1056 bend ina direction to secure the mask to the OCT system that is configured tobe different or opposite in direction to the bending direction of thearmatures and appendages used to constrain the user's head.

In various designs, the area between the apertures acts as a surface onwhich the nasal bridge and forehead rest and thus constrains the headmovement in that direction as well.

A shape of the mask 1032 can be designed to leave gaps 1088 between themask 1032 and the user's head, for example, face, (see, e.g., FIGS. 36B,37 and 38). The gaps 1088 allow room for air to flow between the user'shead and the mask 1032 to prevent fogging. At least some of the gaps1088 may be oriented radially around the center of the user's eyes.

As shown in FIG. 37, the appendages can include a flexible component1080 and a cushion 1084 attached to a proximal end of the flexiblecomponent 1080. Similar to the appendages 1056, the flexible component1080 can flex to accommodate the user's head. The cushion 1084 providesadded comfort to the user. Additionally or alternatively, as shown inFIG. 37, the bridge 1044 of the mask 1032 can include a cushion 1046 foruser comfort and increase the gap 1088 between the user's head and themask 1032. A plurality of contact points between the mask 1032 and theface, for example, created by the cushions, can establish the gaps.

In other configurations, the attachment portions 1024 can extendproximally of a proximal-most end of the mask 1032, such that theattachment portions 1024 and can restrain lateral movement of the user'shead (see FIG. 38A). After the mask 1032 engages the contouredreceptacle 1004, the proximal portions of the attachment portions 1024may flex to accommodate the user's head. As described above, theattachment portions 1024 can be springs biased to the initialconfiguration, such that when the user's head is removed, the attachmentportions 1024 can return to the initial configuration. The proximalportions of the attachment portions 1024 may include cushions 1092 toincrease comfort. Since the cushions 1092 are attached to asemi-permanent part of the device 1024, these cushions may be removableand disposable for hygiene reasons. The mask 1032 can be secured to thereceptacle 1004 by a variety of approaches such as described herein.Similar to earlier embodiments, the shape of the mask 1032 and theattachment portions 1024 can facilitate the creation of the gaps 1088 todecrease fogging. As shown in FIGS. 37 and 38, the nose cushion as partof the mask, constrains the subject's head in one direction.

As discussed above, the contoured portion 1004 can be separatelyattached to the OCT device 1000. FIGS. 39A-42D illustrate a contouredportion 1104 that can be included with a mask 1132. As shown in FIGS.39A-39D, the mask 1132 can comprise an optical transparent window (e.g.,transparent to light wavelengths between 400 nm and 1550 nm or betweenabout 450 nm and 1150 nm). In some configurations, the entire mask 1132may be the optically transparent window. As one example, at least thewindow or optically transparent section can be constructed from PMMAalthough other optically transparent materials may be used. The windowor optically transparent section can be configured with a compoundcurvature (in both X and Y axes) to reduce back-reflections into theoptical coherence tomography device. This curvature in differentmeridians or directions may be the same as in a spherical shape ordifferent as in ellipsoid or paraboloid shapes. In some embodiments,such as when the surface is spherically shaped, this curvature isdefined by a radii of curvature such as for example 25 mm, 40 mm, 50 mm,51 mm, 54 mm, 55 mm or 60 mm or in one or more ranges between any two ofthese radii. Alternatively, the window or optically transparent sectioncan include any of the curvature features described in the other maskembodiments.

The thickness of the window or optically transparent section can beconfigured to be equal across its length or vary with length, such as bythinning in the area in front of each of the user's eyes. See, e.g.,FIGS. 40A-40D in which the region or section 1196 configured to alignwith each of the user's eyes has a reduced thickness to reduceaberration, such as astigmatism. The regions 1196 can have constantreduced thickness. The thickness in these optically transparent regionsor sections 1196 may be between 0.1 mm-0.5 mm, 0.1 mm-1.0 mm 0.1 mm-3.0mm or any other range formed by any of these values. For example, thethickness may be 0.5 mm. This region 1196 may be at least 2 cm², 3 cm²,4 cm², 5 cm², 6 cm², 7 cm², 8 cm², or ranges between any of thesevalues.

In various implementations, the optics of the OCT system, with theaddition of the region(s) or section (s) 1196, are diffraction limitedand have a total RMS wavefront error of less than 0.07 waves. In otherimplementations, the combined RMS wavefront error of some of the opticsof the OCT system and the window region(s) or optically transparentsections(s) 1196 is less than 0.07 waves but the combined wavefronterror of other optics in the OCT system and the windowregion(s)/optically transparent section(s) 1196 is greater than 0.07waves but less than 0.25 waves. In some implementations, the combinedwavefront error of the OCT system and the window region(s) is less forcertain wavelengths or ranges of wavelengths of light, such as 400nm-700 nm and greater for other wavelengths or ranges of wavelengths oflight such as 700 nm-1500 nm. Other configurations that reduce orminimize the combined RMS wavefront error of the optics of the OCTsystem and the window region(s)/section (s) 1196 are possible. Reducedthickness of the regions or sections 1196 through which the beam oflight from the OCT travels to and from the eye may reduce thecontribution of wavefront error. This reduced wavefront error can beuseful in enabling the subject to read an eye chart and may also havethe added benefit of not adversely affecting the OCT signal. Withreduced wavefront error, the OCT optics (and the attached goggles, whicheffectively become part of the optical system) allow a user to see the20/20 E. In this case, the resolution is 1 arc minute on the retina.This low wavefront error may potentially be beneficial for the OCTimaging as well.

The quality of the optical surface, which may be an injection moldedcomponent, also is such that contribution to wavefront error is reduced.In some implementations, the regions or sections 1196 have reducedthickness (e.g., from about 0.25 mm to about 0.5 mm) while the thicknessincreases toward the peripheral regions 1198 or regions peripheral tothe sections 1196 and/or the edges of the mask in one or moredirections, thereby providing mechanical strength. In some embodiments,the thickness may increase for example to 1.0 mm or more in theperipheral regions 1198. These peripheral regions 1198 need not betransparent. Instead these thicker peripheral regions 1198 may betranslucent or opaque or combinations thereof. The peripheral region1198 may also be of less optical quality (e.g., have higher RMS error)than the optically transparent regions 1196.

A single piece comprising the thin regions 1196 and the thickerperipheral region 1198 is one option. These thicker peripheral regions1198 may potentially be translucent or opaque. Other designs can includemultiple pieces such as one or more thin transparent pieces for theregions/sections 1196 and one or more thicker, possibly translucent oropaque, peripheral regions on opposite sides of the windowregion(s)/section (s). The materials used for the multiple pieces maynot be the same. For example, the thin region/section 1196 could be madefrom PMMA or polycarbonate while the peripheral regions 1198 could bemade from ABS or polyethylene. Other materials are possible. In someimplementations, a single molded piece includes the thinregions/sections 1196 and a step or sharp increase in thickness to thethicker peripheral region 1198. Injection molding can be used to formthis single piece or separate thin regions/sections 1196 for multi-piecedesigns which can be assembled into an aggregate structure aftermolding.

As described above, the mask material is preferentially transparent in awindow or window region/section in front of the user's eyes and iscapable of transmitting a wide range of wavelengths of light, such asbetween 400 nm and 1550 nm or at least between 450 nm and 1150 nm. Forexample, the window or window region may be optically transparent overthe ranges 450-650 nm, 750-850, 980-1120, or combinations thereof.Likewise, in various embodiments the window region or section can beoptically transparent over a portion of the visible spectrum and/or aportion of the near-infrared spectrum. In various embodiments, only thethin regions 1196 transmit light with high efficiency (e.g. greater than99.9/%, 99.5%, 99%, 95%, 90%, 80% or 50%) while other areas of the maskmay be opaque or translucent and/or transmit little or no light (e.g.,less than 30%, 20%, 10%, 5%, 1%, or 0% of visible light or any rangedefined by these percentages). The overall base curve 1194 of the mask1132, the curve formed by the left and right optically transparentwindows or sections, and/or the interface between the mask 1132 and theuser can be configured to closely match the curvature of the averagehead to reduce or minimize stand-off distances between the machineoptics and the eye. For example, the base curve may be 8, 10, or 12 orpossible 4, 6, or 8, or any range between any of these values.

The mask 1132 (e.g., FIGS. 41A-42D) can be molded with a contouredreceptacle 1104 or parts thereof, such as the optically transparentsection and peripheral regions can be molded separately and attached tothe contoured receptacle 1104 (see FIGS. 41A-41D). The contouredreceptacle 1104 can be molded from a plastic material to make it costefficient and disposable. Providing a contoured receptacle 1104 separatefrom the OCT device 1000 may be useful if the user interface of the OCTdevice 1000 has a planar surface. The contoured receptacle 1104 canprovide a non-planar, contoured surface for receiving at least portionsof the mask 1132, such as transparent sections and/or peripheralsections, and the user's head. The contoured receptacle 1104 can besecured to the OCT device 1000 using fasteners (e.g., locking pins,screws, adhesives, or otherwise). For example, the contoured receptacle1104 can include openings 1105 to receive the fasteners. The openings1105 can be positioned at a periphery of the contoured receptacle (e.g.,at lateral regions of the contoured receptacle 1104).

The contoured receptacle 1104 can include one opening large enough toreceive both of the user's eyes or at least both thinned, opticallytransparent sections or regions 1196. Alternatively, the contouredreceptacle 1104 can include spaced apart apertures that align with theuser's eyes when the contoured receptacle 1104 is attached to the OCTdevice 1000 or align with the optically transparent sections or regions1196.

As shown in FIGS. 42A-42D, a comfortable, deformable portion 1106 (e.g.,formed from silicone rubber, foam, gel, paper, or otherwise) can beinterposed between the transparent sections (and possibly peripheralregions thereto) of the mask and the user's head. In various cases, thisdeformable portion 1106 can conform to the user's head for comfort. Thedeformable portion 1106 can be more flexible than the opticallytransparent section 1196 and the peripheral regions 1198 the mask 1132and can constrain movement of the user's head when engaged in the mask1132. In some configurations, as shown in FIGS. 42B-42D, the deformableportion 1106 can include an integrated nose shield 1107 to provide ahygienic barrier between the user's nose and the OCT device. In otherconfigurations, the nose shield 1107 can be separately formed from thedeformable portion 1106. The nose shield 1107 can be formed fromsilicone rubber, polyethylene, foam, gel, paper, plastic, or otherwise.The deformable portion 1106 and/or the nose shield 1107 may beinflatable.

As described above, it may be desirable to leave gaps between the maskand the user's head to prevent fogging. The mask 1132 and/or deformableportion 1106 may include recesses or other openings to prevent fogging.Alternatively, the mask 1132 may be coated with an anti-fog composition.

Other configurations of masks 1132, contoured receptacles 1104, anddeformable portions 1106 are imaginable. For example, as shown in FIGS.46A and 46B, the optically transparent sections 1196 and the peripheralregions 1198 (e.g., of FIGS. 39A-39D or 40A-40D) can be secured to adeformable portion 1106, but not a contoured portion 1104. In someinstances, the mask 1132 may be adapted for a contoured portionpermanently fixed to the OCT device. FIGS. 47A and 47B illustrateanother variation in which the mask assembly includes the opticallytransparent sections 1196 and the peripheral regions 1198, the contouredreceptacle 1104, and the deformable portion 1106. However, unlike thecontoured receptacle 1104 shown in FIGS. 41A-41D, an outer periphery ofthe contoured portion 1104 aligns substantially or entirely with anouter periphery of the peripheral regions 1198 surrounding the opticallytransparent sections 1196.

FIGS. 43A-43C illustrate a method of attaching a mask assembly 1200including the optically transparent sections 1196 and the peripheralregions 1198, frame 1104, deformable portion 1106, and/or nose shield1107. FIG. 43A illustrates an OCT device 1100 in an inactive state. TheOCT device 1100 has a shield 1101 over the patient eyepiece portal. Theshield 1101 can be held in place by structures such as spring-loadedsolenoid pins. The spring-loaded pins may comprise solenoids that whenactivated move the pins against the spring force of the spring. Themovement of some solenoids against the spring force of the spring cancause the solenoids to extend their pins. Other solenoids can beconfigured to retract their pins against the spring force when powered.In one embodiment of a shield 1101, holes are configured in the shield1101 to receive spring-loaded pins that extend from a solenoid when thesolenoid is unpowered. In another embodiment of a shield 1101, holes areconfigured in the shield 1101 to receive spring-loaded pins that extendfrom a solenoid when the solenoid is powered. As shown in FIG. 32B, theOCT device 1100 can include a recess 1103 that slidably receives an edgethe mask assembly 1200 (e.g., a lateral edge of the contoured receptacle1104). Although not shown, the recess 1103 can include a microswitchthat causes the solenoids to receive power and retract the pins holdingthe shield 1101. This allows the user to move the shield 1101 (e.g.depress a spring-loaded shield 1101), so the mask assembly 1200 can bemoved into place (see FIG. 43C). When the mask assembly 1200 is inplace, a second microswitch can be triggered to cut power to thesolenoids and allow the spring-loaded pins to engage the mask assembly1200 (e.g., through the openings 1105 in the contoured receptacle 1104).If the second microswitch is triggered without triggering the firstmicroswitch, the machine will know that a user has lifted the shield1101 by hand and will not begin the exam.

FIG. 44 illustrates a method of using an interlock mechanism to preventremoval of the mask 1032 during operation of the OCT device 1000. Whenthe mask 1032 is inserted into the contoured receptacle 1004, the mask1032 can push back spring-loaded solenoid pins in the OCT device 1000 totrigger a first microswitch(es). When the mask 1032 is fully inserted, asecond microswitch(es) can be depressed to indicate full insertion of amask 1032. When the mask 1032 is fully inserted, the OCT device 1000 canpower the spring-loaded solenoid pins to extend into receptacles in themask 1032. The presence of these pins in the mask receptacles willprevent removal of the mask 1032 as long as the solenoids remain in apowered state. When unpowered, the spring-loaded solenoid pins canretract to allow removal of the mask 1032 from the contoured receptacle1032. After the mask 1032 has been removed, the OCT device 1000 canprompt the user to insert a new mask 1032. If an exam is initiated whena microswitch(es) is depressed (i.e. indicating the presence of a mask1032 in the contoured receptacle 1004), the OCT device 1000 can requestthat the user remove the mask from the contoured receptacle 1004 (forexample if the previous subject has left their used mask in the OCTdevice). In other configurations, only one of the microswitches may bepresent or additional microswitches may be present.

As shown in FIGS. 44A-44D, schematically illustrate an embodiment of theinterlock system. In FIG. 44A, the mask 1132 is inserted into thecontoured receptacle 1104 while the OCT device is powered on. As themask 1132 moves toward the contoured receptacle 1104, the mask 1132pushes the spring-loaded solenoid pins 1182 to trigger the switches 1186(see FIG. 44B). In one embodiment, after the mask 1132 is advanced intoengagement with the contour portion 1104, the mask 1132 can trigger themicroswitches 1190 and release microswitches 1186 if the mask 1132 iscorrectly positioned (see FIG. 44C). The OCT device can be configured toonly release the shield or shutter protecting the OCT device and beginexamination when the mask 1132 triggers the microswitches 1190 andreleases microswitches 1187. In some configurations, the solenoid pins1182 can secure the mask 1132 to the OCT device so that it cannot beremoved during operation. After examination is complete, the OCT devicemay instruct the user to remove the mask 1132. In some configurations,if the solenoid pins 1182 are holding the mask 1132 in place, thesolenoid pins 1182 can be deactivated to permit the mask 1132 to beremoved. After the OCT device senses that the mask 1132 has been removed(e.g., from the release of the switches 1190 and/or transient depressionof microswitches 1186), the power to the solenoid pins 1182 can bereactivated and the user can be prompted to insert a mask 1132. Theremay be a timer to create a delay before prompting the user to insert themask 1132. In other configurations, only one of the microswitches may bepresent or additional microswitches may be present. In someconfigurations, the switches are configured to be normally open. Inother configurations, the switches are configured to be normally closed.In addition, in some embodiments, the solenoids are configured to extendtheir pins when unpowered.

FIG. 45 illustrates another embodiment of a disposable mask 1032 and acontoured receptacle 1004 permanently attached to the OCT device (notshown). Similar to FIGS. 34A-34C, the mask 1032 can engage the contouredreceptacle 1004 using a ball detent feature. The armature 1034 caninclude a cutout 1045 at a junction between the attachment portion 1036and the appendage 1056 to reduce a thickness at the junction. The sizeof the cutout 1045 can be used to modify the spring constant of thearmatures 1034. The spring constant gets weaker as the material getsthinner, while the spring constant gets stronger as the material getsthicker. This may be useful to create different masks 1034 for varioushead sizes. Users with large heads may require armatures 1034 withweaker spring constants than users with smaller heads. In otherconfigurations, the spring constant of the armatures 1034 can be variedusing cross-beam supports or different material.

Further, the nose bridge 1044 of the mask 1032 can include acompressible cushion 1046 for user comfort and/or to provide a gapbetween the mask 1032 and the user to prevent fogging. In someembodiments, the mask is reusable. In other embodiments, the mask issingle use or disposable and intended to be used by one patient,subject, or user, and subsequently disposed of and replaced with anothermask for use for another person. In some embodiments, the mask isconfigured for limited re-use (e.g., 2, 3, 4, times etc.) for example byone patient, user, or subject and subsequently disposed of. More thansuch limited use may result in noticeable wear or indications of usage.

In various embodiments, the optical transparent sections 124 of the maskare configured to increase or maximize transmission of light, such asfrom an OCT device, and the proximal portions 154 and concaved rearsurface 122 is configured to reduce or minimize transmission of light,such as ambient light or light not emanating from an OCT machine and maybe opaque and include opaque sides. For example, the proximal portions154 may have sides that are substantially non-transmissive to visiblewavelengths. These sides may for example block 80-90%, 90-95%, 95-99%,and/or 99-100% of ambient visible light. Reduction of ambient light mayfor example assist in keeping the patient's pupils dilated. Conversely,the optically transparent sections may have a transmittance of 70-80%,80-90%, 90-95%, 95-99%, and/or 99-99.5%, or 99.5%-100% or anycombination of these ranges in the wavelength range at which theophthalmic device operates such as at 450 nm, 515 nm, 532 nm, 630 nm,840 nm, 930 nm, 1060 nm, 1310 nm, or any combination thereof or acrossthe visible and/or near IR wavelength range or at least 10%, 20%, 30%,40%, 50%, 60%, 70%, 80%, or 90% of that range.

Methods and configurations for reducing retro-reflection back into theinstrument can be used including any combination of the foregoing suchas a combination of tilt and anti-reflective coatings.

One use for the AR coating on these goggles could be to increasetransmission of emitted light into the eye. Optical instruments thatsense back-reflected light (e.g. imaging instruments) often benefit fromor require very sensitive instrumentation (e.g. avalanche photodiodes,interferometers, etc.) if the level of back-reflected light is low.Additionally, since the tissues in the eye are not very reflective, thelow signal level of light back-reflected from the eye tissue to beimaged or evaluated by the ophthalmic imaging or diagnostic systems maybe lost in noise if the ghost back-reflections are sufficiently high. Asdiscussed above, reducing the optical interfaces that will beperpendicular to the incident beam at any point may advantageouslyreduce back-reflection that introduced noise. Various embodiments,therefore, employ tilting or curving the surface of the window.Additionally, signal can potentially be strengthened by increasingtransmission of light (and consequently by reducing reflections) atsome, many, most, or every surface to increase or maximize power goingboth to and coming from the eye. This goal can be accomplished, forexample, with AR coatings. Advantageously, in various embodiments, thisincreased transmission is accompanied by reduced reflections, whichimprove the signal-to-noise ratio (SNR) and contrast in the images, ordata produced and reduce ghost artifacts that can appear as realobjects, for example, in an OCT or other image. Other instruments maybenefit for similar or different reasons. Although various embodimentsof the mask have been discussed above in connection with an opticalcoherence tomography device the mask may be used with other diagnosticinstruments or devices and in particular other ophthalmic devices suchas a scanning laser ophthalmoscope (SLO).

Anti-Fogging

Any of the hygienic barriers, masks, or goggles described above caninclude one or more features to reduce or prevent fogging. For example,as described above, the mask can have an anti-fog coating. As anotherexample, the mask can be shaped to leave a gap between the mask and theuser's head for ventilation. As described below, in some designs, it maybe desirable to provide a positive air flow source to reduce or preventfogging. Depending on the design, air can be vented into or out of theOCT or other ophthalmic instrument (including ophthalmic diagnosticinstruments). The masks 1300 described below may form the entirety ofthe mask or only a portion of the mask, e.g., the masks 1300 may haveany of the features described herein for attaching the mask to theophthalmic instrument and/or features to facilitate alignment with theuser's face or head.

FIG. 48A, for example, illustrates a mask 1300 that can include any ofthe features (e.g., contours, dimensions, material, etc.) of the masksor goggles described above or elsewhere herein. The mask 1300 caninclude at least one aperture 1310 (e.g., one, two, three, four, ormore) to facilitate air flow through the mask 1300. The aperture(s) 1310can be positioned anywhere on the mask 1300 that avoids obstructing theeye exam (e.g., outside the light transmission region of the opticallytransmissive section(s)), for example, at a periphery of the mask 1300.In some implementations, at least one aperture 1310 can be positionednear each lateral edge 1320 of the mask 1310 (e.g., closer to a lateraledge 1320 of the mask 1300 than a longitudinal axis L of the mask 1300).In some implementations, at least one aperture 1310 can be positionedcloser to an edge of the anterior portion of the mask than alongitudinal axis L of the mask, such as shown in FIG. 48A, (e.g.,within about 2.0 inches from an edge of the anterior portion, or withinabout 1.0 inch from the edge of the anterior portion). In alternative orin addition to the aperture(s) 1310 at the lateral periphery, one ormore apertures 1310 can be positioned near an upper edge 1304 of themask 1300 (e.g., closer to an upper edge 1304 of the mask 1300 than atransverse axis (perpendicular to the longitudinal axis L) of the mask1300) (see FIG. 48F), positioned near a lower edge 1308 of the mask 1300(e.g., closer to an lower edge 1308 of the mask 1300 than a transverseaxis (perpendicular to the longitudinal axis L) of the mask 1300) (seeFIG. 48E). In these configurations, the one or more apertures may bewithin about 1.0 inches or within about 0.5 inches from an upper and/orlower edge of the mask 1300. In some configurations, one or moreapertures 1310 may be positioned at a central or nasal bridge portion1312 of the mask 1300 (see FIG. 48D). In some configurations, apertures1310 can be positioned in different locations across the mask (see FIG.48G), including at the transition 1325 between the anterior portion 1305of the mask and the armatures 1315. The mask 1300 may also includeapertures 1310 in the nose region 1312 of the mask. If the mask includesproximally extending armatures 1315, the mask may also include apertures1310 to facilitate the transmission of audio to the user's ears. Forexample, the OCT or ophthalmic instrument may include speakers for theears and the holes may transmit the audio from the speakers to the ears.The armatures in such instance provide a hygienic barrier with respectto the speakers. In some configurations, the mask 1310 may include aforehead support and/or a portion for receiving or covering the nose(not shown). One or more apertures 1310 may be positioned in theforehead support and or nasal region of that mask. In someconfigurations, the mask 1310 may include a cushion (e.g., along aforehead portion, a nasal bridge portion, a lateral temple portion,and/or otherwise). In those configurations, one or more apertures 1310may be positioned near or directly under the cushion (e.g., closer tothe cushion than a longitudinal or transverse axis of the mask). Inembodiments that include a proximally extending portion (e.g., FIGS. 21Ato 21D), the apertures 1310 can be located anywhere on the proximallyextending portion (e.g., anywhere on proximal portion 254, which may beintegral or separate from distal portion 218), for example on thelateral sides of the mask.

The number and size of the apertures 1310 can be selected to reduce orprevent fogging across the entire anterior surface of the mask 1300. Forexample, in the illustrated embodiment, the mask 1300 can include twoapertures 1310 (or more) positioned near each lateral edge 1320. Theapertures 1310 on each side of the mask 1310 can be positioned along anaxis that is substantially parallel to a longitudinal axis L of the mask1300 (e.g., within about ten degrees of parallel with the longitudinalaxis L). In other configurations, the apertures 1310 can be positionedalong an axis that is substantially perpendicular to a longitudinal axisL of the mask 1300 (e.g., within about ten degrees of perpendicular withthe longitudinal axis L) or can be positioned in any otherconfiguration.

As shown in FIG. 48A, each aperture 1310 can be circular. In otherconfigurations, the perimeter of each aperture 1310 can take on anyother shape, e.g., rounded, elliptical, triangular, rectangular, etc.The apertures 1310 can have the same shape and/or size or differentshapes and/or sizes. The apertures 1310 can be sized to permit an airflow between about 0.001 and about 0.5 L/min, such as between about0.001 and about 0.1 L/min, or between about 0.05 and about 1.5 L/min, orotherwise. The cumulative open area of all of the apertures 1310 can bebetween about 0.05 sq. inches and about 2.0 sq. inches. For example, thecumulative open area of all of the apertures 1310 can be between about0.05 sq. inches and about 0.5 sq. inches, between about 0.25 sq. inchesand about 0.75 sq. inches, between about 0.5 sq. inches and about 1.0sq. inches, between about 0.75 sq. inches and about 1.25 sq. inches, anyranges between any of these values, or otherwise. This total cumulativeopen area can be accomplished using a single aperture 1310 or aplurality of apertures 1310. If the total cumulative open area is lessthan 0.05 sq. inches, there may be an increase in the static pressure inthe system, which may lead to the use of pumps (e.g., vacuum systems,blowers, or otherwise) that are louder and/or heavier to providesufficient air flow. Excess noise may interfere with any voicerecognition programming incorporated into the ophthalmic instrument. Invarious implementations, total cumulative noise level of the suctionsystems or pumps is no greater than about 50 dBa, no greater than about40 dBa, no greater than about 35 dBA, no greater than about 30 dBa, nogreater than about 25 dBa, no greater than about 20 dBa, or any otherrange between any of these values.

In the illustrated embodiment, the at least one aperture 1310 is anopening. As shown in FIG. 48A, there is no extension or other protrusionextending from a periphery of any of the aperture 1310. For example, incertain implementations no elongate tube extends from the periphery ofthe aperture. Likewise, in certain implementations no elongate tubularsection extends from the periphery of the aperture. In certainimplementations, no annular ring extends from the periphery of theaperture. Similarly, in certain implementations, no hollow cylindricalsection (e.g., right circular cylinder or other cylinder having a hollowinner region) extends from the periphery of the aperture. Accordingly,in certain implementations the thickness of the periphery of theaperture 1310 may be no more than 1 mm thicker than the surrounding oradjacent surface which may, for example, be part of the transparentsections (or non-transparent sections) configured to be opticallyinterfaced with the docking portion of the ophthalmic instrument. Incertain implementations the thickness of the periphery of the aperture1310 may less than 0.5 mm, less than 0.2 mm, or less than 0.1 mm thickerthan the surrounding or adjacent surface which may, for example, be partof the transparent sections (or non-transparent sections) configured tobe optically interfaced with the docking portion of the ophthalmicinstrument. A surface surrounding each aperture 1310 can be generallyplanar, tapered, curved or combinations of these shapes. In certainimplementations, the thickness of the periphery of the aperture 1310 maybe the same thickness or substantially the same thickness as the surfacesurrounding each aperture 1310. In some configurations, however, theremay be an adapter, flange, tube, tubular section, or other connectionfeature possibly for connecting a device that facilitates air flow(e.g., vacuum, fan, etc.).

In some scenarios, it may be desirable to include a registration featuresurrounding or at a periphery of one or more apertures 1310 (e.g., aperiphery of individual apertures 1310 or a subset of apertures 1310).The registration feature may register the mask 1300 in the cradleportion 1350 of the ophthalmic instrument. In some implementations, thisregistration feature can prevent the mask from moving within the cradleportion 1350 and/or act as a mechanical or electromechanical safetyinterlock that prevents the system from operating unless the mask 1300is properly positioned.

As shown in FIG. 48C, the OCT instrument or other ophthalmic system caninclude a cradle portion 1350 (also referred to herein as a dockingportion) for receiving the mask 1300 (e.g., within a recess or slot orotherwise). The cradle portion 1350 may be integral with the othercomponents of the ophthalmic system or a completely separate structure.The contours of a surface 1370 of the cradle portion 1350 can correspondto the contours of the mask 1300 (e.g., mirror each other or otherwisebe counterparts). When assembled, the mask 1300 can be in closeproximity to the surface 1370 of the cradle portion 1350 to increase ormaximize the amount of air extracted from between the mask 1300 and theuser. If there is a gap between the mask 1300 and the cradle portion1350, the suction system may be less efficient.

The cradle portion 1350 can include at least one aperture 1360 (e.g.,one, two, three, four, or more) to facilitate air flow, for examplesuction, through the mask 1300. When the mask 1300 interfaces with thecradle portion 1350, each aperture 1310 of the mask 1300 can be in fluidcommunication with an aperture 1360 of the cradle portion 1350 (e.g., atleast partially aligned) such that air flows through the aperture(s)1310 of the mask 1300 and the aperture(s) 1360 of the cradle portion1350. At least one aspect of each aperture 1360 of the cradle portion1350 (e.g., size, shape, and/or position of the apertures) cancorrespond with an aspect of a corresponding aperture 1310 of the mask1300 to provide the alignment.

Each aperture 1360 of the cradle portion 1350 can be in fluidcommunication with a channel 1370 extending at least partially throughthe cradle portion 1350 (see FIGS. 49 to 51). Each aperture 1360 can bein fluid communication with a separate channel 1370 or two moreapertures 1360 can correspond to a single channel 1370. In someconfigurations, each channel 1370 can extend from a first side 1352 ofthe cradle portion 1350 to an opposite side 1354 of the cradle portion1350 (see FIG. 49). A longitudinal axis of each channel 1370 can besubstantially parallel to a longitudinal axis L of the cradle portion1350 (e.g., within about ten degrees of parallel). In otherconfigurations, each channel 1370 can extend from a first side 1352 ofthe cradle portion 1350 to a lateral edge 1356 of the cradle portion1350. The channels 1370 may extend obliquely toward the lateral edge1356 or may include one or more turns 1358 (see FIG. 50). In otherconfigurations, each channel 1370 can extend obliquely from a first side1352 of the cradle portion 1350 to an opposite side 1354 of the cradleportion 1350 (see FIG. 51). As shown in FIG. 51, the channels 1370 mayextend obliquely toward a centerline of the cradle portion 1350 andconverge at a single outlet 1372 on the opposite side 1354 of the cradleportion 1350.

As described above, it can be desirable to provide an air flow, forexample suction, through the mask 1300 at a rate between about 0.001 andabout 0.5 L/min. Below this range, air flow can be too low to preventfogging. Above this range, air flow can be too high and may beuncomfortable or dry out the user's eyes. The channels 1370 can be sizedto reduce the amount of static pressure and resistance the pumps have toovercome.

The cumulative cross-sectional area of the channels 1370 (takentransverse to a longitudinal axis of each respective channel 1370) canfall within the same range as the cumulative open area of the apertures1310 of the mask. The cumulative cross-sectional area of all of thechannels 1370 can be between about 0.05 sq. inches and about 2.0 sq.inches. For example, the cumulative cross-sectional area of all of thechannels 1370 can be between about 0.05 sq. inches and about 0.5 sq.inches, between about 0.25 sq. inches and about 0.75 sq. inches, betweenabout 0.5 sq. inches and about 1.0 sq. inches, between about 0.75 sq.inches and about 1.25 sq. inches, any ranges between any of thesevalues, or otherwise.

A length of each channel 1370 can be between about 0.5 inches and about24.0 inches, for example, between about 0.5 inches and about 6 inches,between about 3 inches and about 9 inches, between about 6 inches andabout 12 inches, between about 9 inches and about 15 inches, betweenabout 12 inches and about 18 inches, between about 15 inches and about21 inches, between about 18 inches and about 24 inches, any rangesbetween any of these values, or otherwise. For a curved or bent channel1370 (e.g., as shown in FIG. 50), the length can be measured along acenterline extending from a channel inlet to a channel outlet.

FIGS. 49 to 51 schematically illustrate systems 1400 with differentchannel configurations and positive air flow systems. The system 1400may include one or more suction systems 1390 (e.g., venturi vacuum pump,rotary vane pump, diaphragm pump, piston pump, scroll pump, fan, etc.).For example, the system 1400 can include a single suction system 1390(see FIG. 51) or two suction systems 1390 for each side of the mask (seeFIGS. 49 and 50). The suction system(s) 1390 can be in fluidcommunication with the channel(s) 1370 (e.g., within the channel orexternal to the channel) through an air tight connection. The variousfeatures in FIGS. 49 to 51 can be used interchangeably. Although thesystems below describe the use of suction systems 1390, in otherconfigurations, air flow may be passive or air may be delivered to theregion between the mask 1300 and the user.

As shown in FIG. 49, each aperture 1310 of the mask 1300 can be at leastpartially aligned with a corresponding aperture 1360 in the cradleportion 1350. Each aperture 1360 of the cradle portion 1350 can be influid communication with a channel 1370. Each of the channels 1370 canextend substantially linearly from a first side 1352 of the cradleportion 1350 to an opposite side 1354 of the cradle portion 1350. Eachchannel 1370 can be in fluid communication with a suction system 1390(illustrated as a venturi vacuum pump). Each suction system 1390 can beconnected to a respective outlet end 1372 of a channel 1370 through anumber of airtight ports or seals 1385 and air hoses 1380. The suctionsystems 1390 can pump air from between the mask 1300 and the user,through the channels 1370, and out of the suction systems 1390.

As shown in FIG. 50, each aperture 1310 of the mask 1300 can be at leastpartially aligned with a corresponding aperture 1360 in the cradleportion 1350. Each aperture 1360 of the cradle portion 1350 can be influid communication with a channel 1370. Each of the channels 1370 canextend from a first side 1352 of the cradle portion 1350 to a lateralside 1356 of the cradle portion 1350 through at least one turn 1358(e.g., curved or angular turn). Each turn 1358 can form an angle of lessthan or equal to about 90 degrees and/or at least about 5 degrees, forexample, less than or equal to about 75 degrees, less than or equal toabout 60 degrees, less than or equal to about 45 degrees, ranges betweenthese values, or otherwise. Each channel 1370 can be in fluidcommunication with suction system 1390 (illustrated as a blower). Asshown, each suction system 1390 is positioned within a channel 1370, butin other configurations, the suction systems 1390 may be positionedoutside of the channels 1370. The suction systems 1390 can pump air frombetween the mask 1300 and the user, through the channels 1370, and outof the cradle portion 1350.

As shown in FIG. 51, each aperture 1310 of the mask 1300 can be at leastpartially aligned with a corresponding aperture 1360 in the cradleportion 1350. Each aperture 1360 of the cradle portion 1350 can be influid communication with a channel 1370. Each of the channels 1370 canextend obliquely from a first side 1352 of the cradle portion 1350 to anopposite side 1354 of the cradle portion 1350. The channels 1370 canconverge at a single outlet 1372. The outlet 1372 can be in fluidcommunication with a suction system 1390 through a number of airtightports/seals 1385 and/or air hoses 1380. The suction system 1390 can pumpair from between the mask 1300 and the user, through the channels 1370,and out of the suction system 1390.

Terminology

While the invention has been discussed in terms of certain embodiments,it should be appreciated that the invention is not so limited. Theembodiments are explained herein by way of example, and there arenumerous modifications, variations and other embodiments that may beemployed that would still be within the scope of the present invention.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures of the invention are described herein. It is to be understoodthat not necessarily all such advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves one advantage or groupof advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

As used herein, the relative terms “temporal” and “nasal” shall bedefined from the perspective of the person wearing the mask. Thus,temporal refers to the direction of the temples and nasal refers to thedirection of the nose.

As used herein, the relative terms “superior” and “inferior” shall bedefined from the perspective of the person wearing the mask. Thus,superior refers to the direction of the vertex of the head and inferiorrefers to the direction of the feet.

As used herein, the relative terms “anterior” and “posterior” shall bedefined from the perspective of the person wearing the mask. Thus,anterior refers to the direction of the user's face and inferior refersto the direction of the back of the user's head.

As used herein, the relative terms “proximal” and “distal” shall bedefined from the perspective of the person near the mask. Thus, proximalrefers the direction of the person and distal refers to the directionaway from the person.

The term mask is used herein to include an interface for the subjectthat is to be disposed between the patient's eyes and the ophthalmicinstrument. This interface need not be secured to the subject when thesubject is away from the instrument. Similarly, the term wear or worn isused in connection with the mask being disposed with respect to thesubject's head and/or face such that the mask is between the patient'seyes and the ophthalmic instrument when the exam is performed. The termwear or wearer therefore applies to the subject regardless of whether(i) the interface is secured to the subject when the subject is awayfrom the instrument or (ii) the subject uses the mask when the mask isinserted into the docking portion or receptacle on the ophthalmicinstrument and the interface is not secured to the subject when thesubject is away from the instrument.

Terms such as “above,” “below,” “bottom,” “top,” “side,” “higher,”“lower,” “upper,” “over,” and “under,” are from the perspective of theperson wearing the mask. Thus, upper is closer to the vertex of the headthan lower when the person is using the OCT device.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments.

The terms “comprising,” “including,” “having,” and the like aresynonymous and are used inclusively, in an open-ended fashion, and donot exclude additional elements, features, acts, operations, and soforth. Also, the term “or” is used in its inclusive sense (and not inits exclusive sense) so that when used, for example, to connect a listof elements, the term “or” means one, some, or all of the elements inthe list.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately”, “about”, and “substantially” may refer to an amountthat is within less than 10% of the stated amount, as the context maydictate.

The ranges disclosed herein also encompass any and all overlap,sub-ranges, and combinations thereof. Language such as “up to,” “atleast,” “greater than,” “less than,” “between” and the like includes thenumber recited. Numbers preceded by a term such as “about” or“approximately” include the recited numbers. For example, “about 450 nm”includes “450 nm.”

Components can be added, removed, and/or rearranged. Further, thedisclosure herein of any particular feature, aspect, method, property,characteristic, quality, attribute, element, or the like in connectionwith various embodiments can be used in all other embodiments set forthherein. Additionally, it will be recognized that any methods describedherein may be practiced using any device suitable for performing therecited steps.

Moreover, while illustrative embodiments have been described herein, thescope of any and all embodiments having equivalent elements,modifications, omissions, combinations (e.g., of aspects across variousembodiments), adaptations and/or alterations as would be appreciated bythose in the art based on the present disclosure. The limitations in theclaims are to be interpreted broadly based on the language employed inthe claims and not limited to the examples described in the presentspecification or during the prosecution of the application, whichexamples are to be construed as non-exclusive. Further, the actions ofthe disclosed processes and methods may be modified in any manner,including by reordering actions and/or inserting additional actionsand/or deleting actions. It is intended, therefore, that thespecification and examples be considered as illustrative only, with atrue scope and spirit being indicated by the claims and their full scopeof equivalents.

Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication.

What is claimed is:
 1. A mask for performing an eye exam using anophthalmic instrument, the ophthalmic instrument operable to direct anincident light beam to a subject's eyes and receive a reflected orscattered light beam from the subject's eyes, the mask comprising: oneor more optically transparent sections configured to be opticallyinterfaced with a docking portion of the ophthalmic instrument, whereinat least one of the one or more optically transparent sections has aspherical shape and constant thickness over an area of at least 2 cm²for said incident light beam to said subject's eyes and for reflected orscattered light from the subject's eyes to pass through said one or moreoptically transparent sections; a proximal portion having a rear surfacethat faces the subject when in use; and a mask attachment portionconfigured to attach to the ophthalmic instrument thereby restrictingmovement of said mask once attached to said ophthalmic instrument. 2.The mask of claim 1, wherein said one or more optically transparentsections comprise an anterior surface and a posterior surface that arespherical and have the same center of curvature.
 3. The mask of any ofclaims 1-2, wherein said one or more optically transparent sections haveradii of curvature with the range of 30 mm to 70 mm.
 4. The mask of anyof claims 1-3, wherein said one or more optically transparent sectionshas a thickness of between about 0.1 mm and 3.0 mm.
 5. The mask of anyof claims 1-4, wherein said optically transparent section introducesless than 0.07 RMS wavefront error.
 6. The mask of any of claims 1-5,further comprising lateral portions laterally disposed with respect tosaid one or more optically transparent sections.
 7. The mask of claim 1,wherein said one or more optically transparent sections comprises a pairof left and right optically transparent sections for left and right eyesof the subject.
 8. The mask of claim 7, further comprising bridgeportion between said left and right optically transparent sections. 9.The mask of any of claims 1-8, wherein said one or more opticallytransparent sections are piano.
 10. The mask of any of claims 1-8,wherein one or more of said optically transparent sections have opticalpower.
 11. A mask for performing an eye exam using an ophthalmicinstrument, the ophthalmic instrument operable to direct an incidentlight beam to a subject's eyes and receive a reflected or scatteredlight beam from the subject's eyes, the mask comprising: one or moreoptically transparent sections configured to be optically interfacedwith a docking portion of the ophthalmic instrument, wherein at leastone of the one or more optically transparent sections has a constantthickness over an area of at least 2 cm² for said incident light beam tosaid subject's eyes and for reflected or scattered light from thesubject's eyes to pass through said one or more optically transparentsections; a proximal portion having a rear surface that faces thesubject's face when in use; and a mask attachment portion configured toattach to the ophthalmic instrument thereby restricting movement of saidmask once attached to said ophthalmic instrument.
 12. The mask of claim11, wherein said one or more optically transparent sections comprises anellipsoidal surface.
 13. The mask of claim 11, wherein said one or moreoptically transparent sections comprises a paraboloid surface.
 14. Themask of any of claims 11-13, wherein said one or more opticallytransparent sections has a thickness of between about 0.1 mm and 3.0 mm.15. A mask for performing an eye exam using an ophthalmic instrument,the ophthalmic instrument operable to direct an incident light beam to asubject's eyes and receive a reflected or scattered light beam from thesubject's eyes, the mask comprising: one or more optically transparentsections configured to be optically interfaced with a docking portion ofthe ophthalmic instrument such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; a proximalportion having a rear surface that faces the subject's face when in use;and a mask attachment portion configured to attach to the ophthalmicinstrument thereby restricting movement of said mask once attached tosaid ophthalmic instrument, wherein said mask comprises resilientbendable material that deforms when said mask is inserted in a dockingportion of said ophthalmic instrument to facilitate securing said maskto said ophthalmic instrument via said mask attachment.
 16. The mask ofclaim 15, wherein said resilient bendable material is sufficientlyresilient and bendable to disengage said mask attachment portion fromsaid ophthalmic instrument.
 17. The mask of any of claims 15-16, furthercomprising appendages comprising said mask attachment portion, saidappendages being movable with deformation of said resilient bendablematerial so as to secure said mask to said ophthalmic instrument anddisengage said mask from said ophthalmic instrument.
 18. The mask ofclaim 17, further comprising cushioned contact portions on saidappendages for contact with the subject.
 19. The mask of any of claims15-18, wherein said resilient bendable material is biased so as not tobe as deformed upon removal by said subject.
 20. A mask for performingan eye exam using an ophthalmic instrument, the ophthalmic instrumentoperable to direct an incident light beam to a subject's eyes andreceive a reflected or scattered light beam from the subject's eye, themask comprising: one or more optically transparent sections configuredto be optically interfaced with a docking portion of the ophthalmicinstrument such that said incident light beam to said subject's eyes andreflected or scattered light from the subject's eyes pass through saidone or more optically transparent sections; a proximal portion having arear surface that faces the subject's face when in use; and a maskattachment portion configured to attach to the ophthalmic instrumentthereby restricting movement of said mask once attached to saidophthalmic instrument, wherein the mask includes a plurality of spacedapart contact points for contacting the subject such that air gaps areprovided between said mask and the subject to permit air flow.
 21. Themask of claim 20, wherein said plurality of contact points comprisecushioned contact points.
 22. The mask of any of claims 20-21, furthercomprising a plurality of appendages disposed laterally with respect tosaid optically transparent sections, at least some of said contact pointbeing on said appendages.
 23. The mask of any of claims 20-22, whereinsaid one or more optically transparent sections comprises left and righttransparent sections for said left and right eyes of said subject, saidmask further comprising a bridge between said left and right transparentsections.
 24. The mask of claim 23, wherein one of said contact pointsis included on said bridge.
 25. The mask of claim 24, wherein saidcontact point on said bridge comprises a cushion on said bridge.
 26. Amask for performing an eye exam using an ophthalmic instrument, theophthalmic instrument operable to direct an incident light beam to asubject's eyes and receive a reflected or scattered light beam from thesubject's eyes, the mask comprising: one or more optically transparentsections configured to be optically interfaced with a docking portion ofthe ophthalmic instrument such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; a proximalportion having a rear surface that faces the subject's face when in use;a mask attachment portion configured to attach to the ophthalmicinstrument thereby restricting movement of said mask once attached tosaid ophthalmic instrument; and one or more shields disposed to separatesaid subject from said ophthalmic instrument.
 27. The mask of claim 26,wherein at least one of said shields is disposed superiorly with respectto said one or more optically transparent sections to separate asubject's forehead from said ophthalmic instrument.
 28. The mask of anyof claims 26-27, wherein at least one of said shields is disposedinferiorly with respect to said one or more optically transparentsections to separate a subject's nose from said ophthalmic instrument.29. An ophthalmic instrument for performing an eye exam of a subject,the instrument comprising: a light source and optics configured todirect an incident light beam onto the subject's eyes and receive areflected or scattered light beam from the subject's eyes, a dockingportion configured to receive a mask to be worn by the subject, saidmask comprising a proximal portion configured to contact the subject'sface and a distal portion configured to mate with said docking portion,said mask including one or more optically transparent sections alignedsuch that said incident light beam to said subject's eyes and reflectedor scattered light from the subject's eyes to pass through said one ormore optically transparent sections, an attachment portion configured toattach to the mask thereby restricting movement of said mask onceattached to said ophthalmic instrument, wherein said docking stationcomprises a contoured receptacle shaped so as to receive and mate withsaid distal portion of said mask.
 30. The instrument of claim 29,wherein said contoured receptacle is conformally shaped to receive aportion of said mask configured to receive a nose of a subject.
 31. Theinstrument of any of claims 29-30, wherein said contoured receptacle isconformally shaped for receiving a mask having a base curvature ofgreater than base
 6. 32. The instrument of any of claims 29-31, whereinsaid contoured receptacle is conformally shaped for receiving a maskhaving curved optically transparent surfaces as said distal portion. 33.The instrument of any of claims 29-32, wherein said contoured receptacleis conformally shaped for receiving a mask having spherically shapedoptically transparent surfaces as said distal portion.
 34. Theinstrument of any of claims 29-33, wherein the attachment portion isconfigured to receive a corresponding mask attachment portion on saidmask to secure said mask to said instrument.
 35. An ophthalmicinstrument for performing an eye exam of a subject, the instrumentcomprising: a light source and optics configured to direct an incidentlight beam onto the subject's eyes and receive a reflected or scatteredlight beam from the subject's eyes; a docking portion configured toreceive a mask to be worn by the subject, said mask comprising aproximal portion configured to contact the subject's face and a distalportion configured to mate with said docking portion, said maskincluding one or more optically transparent sections aligned such thatsaid incident light beam to said subject's eyes and reflected orscattered light from the subject's eyes pass through one or moreoptically transparent sections; and an attachment portion configured toattached to the mask thereby restricting movement of said mask onceattached to said ophthalmic instrument, wherein said attachment portioncomprises resilient bendable material that deforms when said dockingportion receives said mask to facilitate securing said mask to saidophthalmic instrument via said attachment.
 36. The instrument of claim35, wherein said attachment portion is configured to receive acorresponding mask attachment portion on said mask to secure said maskto said instrument.
 37. The instrument of any of claims 35-36, whereinattachment portion is configured to be further deformed manually by thesubject when the mask is in said docking portion to disengage theattachment portion of the instrument from the mask to remove said maskfrom said docking portion.
 38. The instrument of any of claims 35-37,wherein said resilient bendable material is sufficiently resilient andbendable to disengage said mask from said attachment portion.
 39. Theinstrument of any of claims 35-38, wherein resilient bendable materialis biased so as not to be deformed upon removal of said mask from saiddocking portion.
 40. An ophthalmic instrument for performing an eye examof a subject, the instrument comprising: a light source and opticsconfigured to direct an incident light beam onto the subject's eyes andreceive a reflected or scattered light beam from the subject's eyes; adocking portion configured to receive a mask to be worn by the subject,said mask comprising a proximal portion configured to contact thesubject's head and a distal portion configured to mate with said dockingportion, said mask including one or more optically transparent sectionsaligned such that said incident light beam to said subject's eyes andreflected or scattered light from the subject's eyes to pass throughsaid one or more optically transparent sections; an attachment portionconfigured to attach to the mask thereby restricting movement of saidmask once attached to said ophthalmic instrument; and one or moreshields disposed to separate said subject from said ophthalmicinstrument.
 41. The instrument of claim 40, wherein at least one of saidshields is disposed superiorly with respect to said one or moreoptically transparent sections to separate a subject's forehead fromsaid ophthalmic instrument.
 42. The instrument of any of claims 40-41,wherein at least one of said shields is disposed inferiorly with respectto said one or more optically transparent sections to separate asubject's nose from said ophthalmic instrument.
 43. The instrument ofany of claims 40-41, wherein at least one of said shields is disposedbelow a least one opening in the instrument providing access to saidlight source and optics, said at least one shield to separate asubject's nose from said ophthalmic instrument.
 44. An ophthalmicinstrument for performing an eye exam of a subject, the instrumentcomprising: a light source and optics configured to direct an incidentlight beam onto the subject's eyes and receive a reflected or scatteredlight beam from the subject's eyes; a docking portion configured toreceive a mask to be worn by the subject, said mask comprising aproximal portion configured to contact the subject's head and a distalportion configured to mate with said docking portion, said maskincluding one or more optically transparent sections aligned such thatsaid incident light beam to said subject's eyes and reflected orscattered light from the subject's eyes pass through said one or moreoptically transparent sections; and an attachment portion configured toattach to the mask thereby restricting movement of said mask onceattached to said ophthalmic instrument, wherein said attachment portioncomprises one or more spring loaded extensions configured to mate withthe mask to secure the mask to the docking portion.
 45. The instrumentof claim 44, wherein said one or more spring loaded extensions comprisesa spring loaded pin.
 46. The instrument of claim 44, wherein said one ormore spring loaded extensions comprises a ball detent.
 47. A mask forperforming an eye exam using an ophthalmic instrument, the ophthalmicinstrument operable to direct an incident light beam to a subject's eyesand receive a reflected or scattered light beam from the subject's eyes,the mask comprising: one or more optically transparent sectionsconfigured to be optically interfaced with a docking portion of theophthalmic instrument such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; a proximalportion having a rear surface that faces the subject's head when in use;and a mask attachment portion configured to attach to the ophthalmicinstrument thereby restricting movement of said mask once attached tosaid ophthalmic instrument, wherein said mask attachment portioncomprises one or more holes configured to receive one or more extensionsfrom said docking portion of the ophthalmic instrument.
 48. The mask ofclaim 47, wherein said one or more holes comprise at least one hole oneach of left and right sides of said mask.
 49. The mask of claim 47,wherein said one or more holes comprise at least two holes on each ofleft and right sides of said mask.
 50. An ophthalmic instrument forperforming an eye exam of a subject, the instrument comprising: a lightsource and optics configured to direct an incident light beam onto thesubject's eyes and receive a reflected or scattered light beam from thesubject's eyes; a docking portion configured to receive a mask to beworn by the subject, said mask comprising a proximal portion configuredto contact the subject's head and a distal portion configured to matewith said docking portion, said mask including one or more opticallytransparent sections aligned such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; anattachment portion configured to attach to the mask thereby restrictingmovement of said mask once attached to said ophthalmic instrument, and ashutter disposed in a first position to block a path to said lightsource and optics when a mask is not mated with said docking portion,said shutter configured to be moved from said first position into asecond position when a mask is mated with said docking portion so as topermit incident light beam from said light source onto the subject'seyes and for said optics to receive a reflected or scattered light beamfrom the subject's eyes.
 51. The instrument of claim 50, furthercomprising an actuator configured to move said shutter.
 52. Theinstrument of any of claims 50-51, wherein said shutter is configured tomoved manually.
 53. The instrument of any of claims 50-52, wherein saidshutter is configured to be moved by introducing said mask to saiddocking portion.
 54. The instrument of any of claims 50-53, furthercomprising an actuator to permit movement of said shutter.
 55. Theinstrument of any of claims 50-54, further comprising one or moresensors disposed to sense that a mask has mated with said dockingportion.
 56. The instrument of claim 55, wherein said optics in saidinstrument are configured to move, said movement being stopped when saidshutter is moved from said first position and no mask is detected asbeing mated with said docking station.
 57. An ophthalmic instrument forperforming an eye exam of a subject, the instrument comprising: a lightsource and optics configured to direct an incident light beam onto thesubject's eyes and receive a reflected or scattered light beam from thesubject's eyes; a docking portion configured to receive a mask to beworn by the subject, said mask comprising a proximal portion configuredto contact the subject's head and a distal portion configured to matewith said docking portion, said mask including one or more opticallytransparent sections aligned such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; anattachment portion configured to attached to the mask therebyrestricting movement of said mask once attached to said ophthalmicinstrument, and one or more sensors disposed to sense that a mask hasmated with said docking portion.
 58. The instrument of claim 57, whereinsaid instrument is configured not to perform a measurement of an eyewhen no mask is detected as being mated with said docking station. 59.The instrument of claim 57, wherein said instrument is configured not tomove parts within said instrument that may cause injury when no mask isdetected as being mated with said docking station.
 60. An ophthalmicinstrument for performing an eye exam of a subject, the instrumentcomprising: a light source and optics configured to direct an incidentlight beam onto the subject's eyes and receive a reflected or scatteredlight beam from the subject's eyes; a docking portion configured toreceive a mask to be worn by the subject, said mask comprising aproximal portion configured to contact the subject's head and a distalportion configured to mate with said docking portion, said maskincluding one or more optically transparent sections aligned such thatsaid incident light beam to said subject's eyes and reflected orscattered light from the subject's eyes pass through said one or moreoptically transparent sections; an attachment portion configured toattached to the mask thereby restricting movement of said mask onceattached to said ophthalmic instrument; one or more sensors disposed tosense that a mask is mating with said docking portion; at least onemovable extension configured to mate with the mask to secure the mask tothe docking portion; and an actuator configure to facilitate movement ofsaid movable extensions to engage a mask attachment portion on a maskwhen said one or more sensors senses that the mask is mating with saiddocking portion.
 61. The instrument of claim 60, wherein said at leastone movable extension comprises a spring loaded pin configured to engagesaid mask attachment portion on said mask.
 62. The instrument of claim61, wherein said actuator is configured to move said pin counter to aspring force associated with said spring to disengage said spring loadedpin from said mask.
 63. The instrument of claim 62, wherein saidactuator comprise a solenoid coupled to said spring loaded pin.
 64. Theinstrument of any of claims 60-63, further comprising a shutter disposedin a first position to block a path to said light source and optics whena mask is not mated with said docking portion, said shutter configuredto be moved from said first position into a second position when a maskis mated with said docking portion so as to permit an incident lightbeam from said light source be directed onto the subject's eyes and forsaid optics to receive a reflected or scattered light beam from thesubject's eyes.
 65. The instrument of claim 64, wherein said at leastone movable extension is configured to engage said shutter when said oneor more sensors do not sense that said mask is mating with said dockingstation.
 66. The instrument of any of claims 64-65, wherein said movableextensions are configured to disengage from said shutter when said oneor more sensors detect that said mask is mating with said dockingstation.
 67. A mask for performing an eye exam using an ophthalmicinstrument, the ophthalmic instrument operable to direct an incidentlight beam to a subject's eyes and receive a reflected or scatteredlight beam from the subject's eyes, the mask comprising: one or moreoptically transparent sections configured to be optically interfacedwith a docking portion of the ophthalmic instrument such that saidincident light beam to said subject's eyes and reflected or scatteredlight from the subject's eyes pass through said one or more opticallytransparent sections; a proximal portion having a rear surface thatfaces the subject's face when in use; and a mask attachment portionconfigured to attach to the ophthalmic instrument thereby restrictingmovement of said mask once attached to said ophthalmic instrument,wherein said mask comprises resilient bendable material that deformswhen worn by the subject to facilitate securing said mask to saidophthalmic instrument via said mask attachment when said mask isinserted in a docking portion of said ophthalmic instrument.
 68. Themask of claim 67, wherein said resilient bendable material issufficiently resilient and bendable to disengage said mask attachmentportion from said ophthalmic instrument.
 69. The mask of any of claims67 and 68, further comprising appendages comprising said mask attachmentportion, said appendages being movable with deformation of saidresilient bendable material so as to secure said mask to said ophthalmicinstrument and disengage said mask from said ophthalmic instrument. 70.The mask of claim 69, further comprising cushioned contact portions onsaid appendages for contact with the subject.
 71. The mask of any ofclaims 67-70, wherein said resilient bendable material is biased so asnot to be as deformed upon removal by said subject.
 72. The mask of anyof claims 1-71, wherein said mask is single use.
 73. The mask of any ofclaims 1-71, wherein said mask is configured for limited re-use.
 74. Themask of any of claims 1-73, wherein said one or more opticallytransparent section has an anti-fog coating thereon.
 75. The ophthalmicinstrument of any of claims 1-74, wherein said ophthalmic instrumentcomprises an optical coherence tomography instrument.
 76. The ophthalmicinstrument of any of claims 1-74, wherein said ophthalmic instrumentcomprises an optical scanning laser ophthalmoscope.
 77. The mask of anyof claims 1-76, wherein said mask is not configured to be secured to thesubject when the subject is away from the ophthalmic instrument
 78. Themask of any one of claims 1 to 28, 47 to 49, and 67 to 77, furthercomprising at least one aperture to facilitate air flow.
 79. The mask ofclaim 78, wherein the at least one aperture comprises a plurality ofapertures.
 80. The mask of claim 77 or 78, wherein each aperture ispositioned closer to a lateral edge of the mask than a center of themask.
 81. The ophthalmic instrument of any one of claims 29 to 46, and50 to 66, wherein the docking portion further comprises at least one airchannel and at least one suction system to remove air from between theinstrument and the subject.
 82. The ophthalmic instrument of claim 81,wherein the at least one air channel and the at least one suction systemare configured to facilitate an air flow between about 0.001 L/min andabout 0.5 L/min.
 83. A mask for performing an eye exam using anophthalmic instrument, the ophthalmic instrument operable to direct anincident light beam to a subject's eyes and receive a reflected orscattered light beam from the subject's eyes, the mask comprising: oneor more optically transparent sections configured to be opticallyinterfaced with a docking portion of the ophthalmic instrument such thatsaid incident light beam to said subject's eyes and reflected orscattered light from the subject's eyes pass through said one or moreoptically transparent sections; an attachment feature for attaching themask to the ophthalmic instrument; and at least one aperture positionedin the one or more optically transparent sections, the at least oneaperture permits air flow through the at least one aperture of the maskwhen in use.
 84. The mask of claim 83, wherein each of the at least oneaperture is positioned closer to an outer edge of the mask than thecenter of the mask.
 85. The mask of claim 83 or 84, wherein a total openarea of the at least one aperture is between about 0.5 sq. inches andabout 1.0 sq. inches.
 86. The mask of any one of claims 83 to 85,wherein the at least one aperture comprises a plurality of apertures.87. The mask of any one of claims 83 to 86, wherein the attachmentfeature comprises a flange.
 88. The mask of any one of claims 83 to 87,wherein the attachment feature comprises a spring.
 89. A mask forperforming an eye exam using an ophthalmic instrument, the ophthalmicinstrument operable to direct an incident light beam to a subject's eyesand receive a reflected or scattered light beam from the subject's eyes,the mask comprising: one or more optically transparent sectionsconfigured to be optically interfaced with a docking portion of theophthalmic instrument such that said incident light beam to saidsubject's eyes and reflected or scattered light from the subject's eyespass through said one or more optically transparent sections; anattachment feature for attaching the mask to the ophthalmic instrument;and at least one aperture in a surface of the mask, each of the at leastone aperture is positioned closer to an outer edge of the mask than thecenter of the mask, the at least one aperture permits air to flowthrough the at least one aperture when in use; wherein the aperture hasa periphery with a thickness and the thickness of the periphery of theaperture is no more than 3.0 mm thicker than said surface in which saidaperture is disposed.
 90. The mask of claim 89, wherein the at least oneaperture comprises a plurality of apertures.
 91. The mask of claim 89 or90, wherein the surface comprises said one or more optically transparentsections.
 92. The mask of any one of claims 89 to 91, wherein theattachment feature comprises a flange.
 93. The mask of any one of claims89 to 92, wherein the attachment feature comprises a spring.
 94. Themask of any one of claims 89 to 93, wherein the thickness of theperiphery of the aperture is no more than 2.0 mm thicker than saidsurface in which said aperture is disposed.
 95. The mask of any one ofclaims 89 to 94, wherein the thickness of the periphery of the apertureis no more than 1.0 mm thicker than said surface in which said apertureis disposed.
 96. A mask for performing an eye exam using an ophthalmicinstrument, the mask comprising: one or more optically transparentsections; an attachment feature for attaching the mask to a dockingportion of the ophthalmic instrument; and a first through-hole in ananterior surface of the mask, the first through-hole configured topermit air to flow through the first through-hole when in use.
 97. Themask of claim 96, further comprising a second through-hole in theanterior surface of the mask and configured to permit air to flowthrough the second through-hole when in use.
 98. The mask of claim 96 or97, wherein the first through-hole is closer to a lateral edge of themask than a longitudinal axis of the mask.
 99. The mask of claim 96 or97, wherein the first through-hole is closer to a longitudinal axis ofthe mask than a lateral edge of the mask.
 100. The mask of claim 96 or97, wherein the first through-hole is closer to an upper edge of themask than a transverse axis of the mask.
 101. The mask of claim 96 or97, wherein the first through-hole is closer to a lower edge of the maskthan a transverse axis of the mask.
 102. The mask of any one of claims96 to 101, wherein the first through-hole is positioned in the one ormore optically transparent sections.
 103. The mask of any one of claims96 to 102, wherein the attachment feature comprises a flange.
 104. Themask of any one of claims 96 to 103, wherein the attachment featurecomprises a spring.
 105. The mask of any one of claims 96 to 104,further comprising a registration feature projecting anteriorly andpositioned at a periphery of the first through-hole.
 106. The mask ofany one of claims 96 to 105, wherein a posterior edge of the maskextends no more than 3.0 inches from the anterior surface of the mask.107. The mask of any one of claims 96 to 106, wherein a posterior edgeof the mask extends no more than 2.0 inches from the anterior surface ofthe mask.
 108. The mask of any one of claims 96 to 107, wherein aposterior edge of the mask extends no more than 1.0 inches from theanterior surface of the mask.
 109. A mask for performing an eye examusing an ophthalmic instrument, the mask comprising: one or moreoptically transparent sections; an attachment feature for attaching themask to a docking portion of the ophthalmic instrument; and a firstaperture in the mask, the first aperture configured to permit air toflow through the first aperture when in use, wherein the mask isconfigured not to attach to a head of the user when the head is tilted15 degrees from a longitudinal axis of the user.
 110. The mask of claim109, further comprising a second aperture in the mask and configured topermit air to flow through the second aperture when in use.
 111. Themask of claim 109 or 110, wherein the first aperture is closer to alateral edge of the mask than a longitudinal axis of the mask.
 112. Themask of claim 109 or 110, wherein the first aperture is closer to alongitudinal axis of the mask than a lateral edge of the mask.
 113. Themask of claim 109 or 110, wherein the first aperture is closer to anupper edge of the mask than a transverse axis of the mask.
 114. The maskof claim 109 or 110, wherein the first aperture is closer to a loweredge of the mask than a transverse axis of the mask.
 115. The mask ofany one of claims 109 to 114, wherein the first aperture is positionedin the one or more optically transparent sections.
 116. The mask of anyone of claims 109 to 115, wherein the attachment feature comprises aflange.
 117. The mask of any one of claims 109 to 116, wherein theattachment feature comprises a spring.
 118. The mask of any one ofclaims 109 to 117, further comprising a registration feature projectinganteriorly and positioned at a periphery of the first aperture.
 119. Themask of any one of claims 109 to 118, wherein a posterior edge of themask extends no more than 3.0 inches from the anterior surface of themask.
 120. The mask of any one of claims 109 to 119, wherein a posterioredge of the mask extends no more than 2.0 inches from the anteriorsurface of the mask.
 121. The mask of any one of claims 109 to 120,wherein a posterior edge of the mask extends no more than 1.0 inchesfrom the anterior surface of the mask.
 122. A hygienic barrier for useduring an eye exam using an ophthalmic instrument, the barriercomprising: a first optically transmissive section, the first opticallytransmissive section configured to be optically interfaced with theophthalmic instrument such that, during use, an incident light beam fromthe ophthalmic instrument is transmitted through the first opticallytransmissive section to an eye of a user, the first opticallytransmissive section comprising a light transmission region throughwhich the incident light beam is transmitted; a first aperture in ananterior surface of the hygienic barrier, the first aperture configuredto permit air to flow through the first aperture during the eye exam.123. The hygienic barrier of claim 122, further comprising an attachmentfeature configured to attach the hygienic barrier to the ophthalmicinstrument.
 124. The hygienic barrier of claim 123, wherein theattachment feature comprises a flange.
 125. The hygienic barrier ofclaim 123 or 124, wherein the attachment feature comprises a spring.126. The hygienic barrier of any one of claims 122 to 125, wherein thefirst aperture is in the first optically transmissive section.
 127. Thehygienic barrier of any one of claims 122 to 126, wherein the firstaperture is positioned outside the light transmission region.
 128. Thehygienic barrier of any one of claims 122 to 127, further comprising asecond aperture in the anterior surface of the hygienic barrier. 129.The hygienic barrier of any one of claims 122 to 128, wherein the firstoptically transmissive section forms the entire anterior surface of thehygienic barrier.
 130. The hygienic barrier of any one of claims 122 to128, further comprising a second optically transmissive section. 131.The hygienic barrier of any one of claims 122 to 130, further comprisinga registration feature at a periphery of the first aperture, theregistration feature configured to be received by the ophthalmicinstrument.
 132. The hygienic barrier of any one of claims 122 to 131,wherein the first optically transmissive section comprises a shore Dhardness of at least about
 75. 133. The hygienic barrier of any one ofclaims 122 to 132, wherein the first optically transmissive sectionsections comprise polycarbonate.
 134. The hygienic barrier of any one ofclaims 122 to 132, wherein the first optically transmissive sectionsections comprise PMMA.
 135. The hygienic barrier of any one of claims122 to 134, wherein the light transmission region of the first opticallytransmissive section has a thickness of no more than about 2.0 mm. 136.The hygienic barrier of any one of claims 122 to 135, wherein the lighttransmission region of the first optically transmissive section has asubstantially uniform thickness.
 137. The hygienic barrier of any one ofclaims 122 to 136, wherein the light transmission region has a length ofat least about 20 mm.
 138. The hygienic barrier of any one of claims 122to 137, further comprising armatures extending posteriorly to facilitatealignment of the user with the ophthalmic instrument.
 139. The hygienicbarrier of claim 138, wherein each armature comprises at least onethrough-hole to transmit audio from the ophthalmic instrument.
 140. Thehygienic barrier of claim 138 or 139, wherein a length of each armaturesis no greater than about 3.0 inches.
 141. The hygienic barrier of anyone of claims 122 to 140, wherein the hygienic barrier is a monolithicstructure.
 142. The hygienic barrier of any one of claims 122 to 141,wherein the first aperture has a periphery with a thickness and thethickness of the periphery of the first aperture is no more than 3.0 mmthicker than said anterior surface in which said aperture is disposed.143. The hygienic barrier of any one of claims 122 to 142, wherein themask is configured not to attach to a head of the user when the head istilted 15 degrees from a longitudinal axis of the user.
 144. Thehygienic barrier of any one of claims 122 to 143, wherein the firstaperture is circular.
 145. The hygienic barrier of any one of claims 122to 144, wherein an air flow through the first aperture is between about0.001 L/min and about 0.5 L/min.
 146. The mask of any one of claims 122to 145, wherein the first aperture is positioned closer to an outer edgeof the mask than the center of the mask.
 147. The mask of any one ofclaims 122 to 146, wherein a total open area of the first aperture isbetween about 0.05 sq. inches and about 1.0 sq. inches.
 148. Anophthalmic instrument for performing an eye exam of a subject, theinstrument comprising: a light source and optics configured to direct anincident light beam onto the subject's eyes and receive a reflected orscattered light beam from the subject's eyes, a docking portionconfigured to receive a mask to be worn by the subject, said maskcomprising a proximal portion configured to contact the subject's faceand a distal portion configured to mate with said docking portion, saidmask including one or more optically transparent sections aligned suchthat said incident light beam to said subject's eyes and reflected orscattered light from the subject's eyes to pass through said one or moreoptically transparent sections, an attachment portion configured toattach to the mask thereby restricting movement of said mask onceattached to said ophthalmic instrument, wherein the docking portionfurther comprises at least one air channel and at least one suctionsystem to remove air from between the instrument and the subject.